BARI Bancorp Rhode Island, Inc. (MM)

Use these links to rapidly review the document
TABLE OF CONTENTS
Table of Contents

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A
(Rule 14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.          )

Table of Contents

July 29, 2011

Dear Shareholder:

Your vote is very important.

         On April 19, 2011, the board of directors of Bancorp Rhode Island, Inc. ("BancorpRI") unanimously approved a merger agreement between BancorpRI and Brookline Bancorp, Inc. ("Brookline") pursuant to which BancorpRI will merge with and into Brookline, whereupon the separate corporate existence of BancorpRI will cease and its subsidiary, Bank Rhode Island, will become a wholly-owned subsidiary of Brookline.

         On behalf of the board of directors and management of BancorpRI, you are cordially invited to attend a special meeting of shareholders, which will be held at The Hotel Providence, 311 Westminster Street, Providence, Rhode Island 02903, on Thursday, September 8, 2011 at 10:00 a.m., local time. At the special meeting, you will be asked to consider and vote upon a proposal to approve the merger agreement. At the special meeting, in addition to the approval of the merger agreement, you will be asked to cast an advisory (non-binding) vote on the "golden parachute" compensation payable to the named executive officers of BancorpRI in connection with the merger. If necessary, you may also be asked to vote on a proposal to adjourn the special meeting to permit the further solicitation of proxies.

         If the merger agreement is approved and the merger is subsequently completed, each outstanding share of BancorpRI common stock will be converted into the right to receive, at the election of the shareholder and subject to the allocation and proration procedures described in the merger agreement, either: (1) $48.25 in cash, without interest (which we refer to as the cash consideration); or (2) 4.686 shares of Brookline common stock (which we refer to as the stock consideration). The cash consideration will remain fixed while the value of the stock consideration will fluctuate with the market price of Brookline common stock. All elections are subject to allocation and proration procedures that are intended to ensure that 2,347,000 shares of BancorpRI common stock, or approximately 50% of the total number of shares of BancorpRI common stock outstanding immediately prior to the effective time of the merger, will be converted into shares of Brookline common stock, and the remaining shares of BancorpRI common stock will be converted into cash. The maximum number of shares of Brookline common stock estimated to be issuable upon completion of the merger is 10,998,042. Brookline common stock is traded on the NASDAQ Global Select Market under the symbol "BRKL" and BancorpRI common stock is traded on the NASDAQ Global Select Market under the symbol "BARI." On July 28, 2011, the closing price of Brookline common stock was $8.60 per share and the closing price of BancorpRI common stock was $43.98 per share.

         The merger cannot be completed unless a majority of the shares of BancorpRI common stock outstanding and entitled to vote at the special meeting approve the merger agreement. The BancorpRI board of directors unanimously approved the merger agreement and determined that the merger is advisable and in the best interests of BancorpRI and its shareholders, and unanimously recommends that shareholders vote "FOR" approval of the merger agreement. The BancorpRI board of directors further recommends that the shareholders vote "FOR" approval, on an advisory (non-binding) basis, of the golden parachute compensation payable to the named executive officers of BancorpRI in connection with the merger, and "FOR" the adjournment proposal.

         Whether or not you plan to attend the special meeting, please take the time to vote by using the internet, by telephone or by completing the enclosed proxy card and returning it in the enclosed postage paid envelope, so that your shares may be represented at the meeting. If you hold shares through a bank or broker, please use the voting instructions you have received from your bank or broker. If you sign, date and mail your proxy card without indicating how you want to vote, your proxy will be counted as a vote "FOR" approval of the merger agreement and the other proposals. If you fail to vote, or you do not instruct your broker how to vote any shares held for you in "street name," it will have the same effect as voting "AGAINST" the proposal to approve the merger agreement but will have no impact on the outcome of the other proposals.

         The accompanying document serves as the proxy statement for the special meeting of shareholders of BancorpRI and the prospectus for the shares of Brookline common stock to be issued in connection with the merger. This proxy statement/prospectus describes the special meeting, the merger, the documents related to the merger and other related matters. We urge you to read this entire document carefully. In particular, you should carefully consider the discussion in the section of the proxy statement/prospectus titled "Risk Factors" beginning on page 24.

		Very truly yours,
		John A. Yena, Chairman

          Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the merger, the issuance of the Brookline common stock in connection with the merger or the other transactions described in this proxy statement/prospectus, or passed upon the adequacy or accuracy of the disclosure in this document. Any representation to the contrary is a criminal offense.

          The securities to be issued in connection with the merger are not savings accounts, deposits or other obligations of any bank or savings association and are not insured by the Federal Deposit Insurance Corporation or any other governmental agency.

         This proxy statement/prospectus is dated July 29, 2011 and is first being mailed to shareholders of BancorpRI on or about August 5, 2011.

Table of Contents

BANCORP RHODE ISLAND, INC.
One Turks Head Place
Providence, Rhode Island 02903

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS
TO BE HELD ON SEPTEMBER 8, 2011

To the Shareholders of Bancorp Rhode Island, Inc.:

        A special meeting of shareholders of Bancorp Rhode Island, Inc. ("BancorpRI") will be held at The Hotel Providence, 311 Westminster Street, Providence, Rhode Island 02903, on Thursday, September 8, 2011 at 10:00 a.m., local time, for the following purposes:

1.

To consider and vote upon a proposal to approve the Agreement and Plan of Merger by and between BancorpRI and Brookline Bancorp, Inc. ("Brookline"), dated as of April 19, 2011, pursuant to which BancorpRI will merge with and into Brookline, whereupon the separate corporate existence of BancorpRI will cease and its subsidiary, Bank Rhode Island, will become a wholly-owned subsidiary of Brookline;



2.

To consider and vote upon an advisory (non-binding) proposal to approve the golden parachute compensation payable to the named executive officers of BancorpRI in connection with the merger;



3.

To consider and vote upon a proposal to approve one or more adjournments of the special meeting, if necessary, to permit further solicitation of proxies if there are not sufficient votes at the time of the special meeting, or at any adjournment or postponement of that meeting, to approve the merger agreement; and



4.

To consider and act upon such other matters as may properly come before the special meeting or any adjournment or postponement of that meeting.

        The merger agreement and the proposed merger of BancorpRI with and into Brookline, is more fully described in the attached proxy statement/prospectus, which you should read carefully and in its entirety before voting. A copy of the merger agreement is included as Annex A to the attached proxy statement/prospectus.

        BancorpRI has established July 27, 2011 as the record date for determining the shareholders entitled to notice of and to vote at the special meeting. Only record holders of BancorpRI common stock as of the close of business on that date will be entitled to vote at the special meeting or any adjournment or postponement of that meeting. The affirmative vote of holders of a majority of the shares of BancorpRI common stock outstanding and entitled to vote at the special meeting is required to approve the merger agreement.

         BancorpRI's board of directors unanimously recommends that you vote "FOR" approval of the merger agreement, "FOR" approval, on an advisory (non-binding) basis, of the golden parachute compensation payable to the named executive officers of BancorpRI in connection with the merger, and "FOR" the adjournment proposal as described above.

Table of Contents

        All shareholders are cordially invited to attend the special meeting. To ensure your representation at the special meeting of shareholders, please follow the voting procedures described in the accompanying proxy statement/prospectus and on the enclosed proxy card. Following these voting procedures will not prevent you from voting in person, but it will help to secure a quorum and allow your shares to be voted should anything prevent your attendance in person. Your proxy may be revoked at any time before it is voted.

		BY ORDER OF THE BOARD OF DIRECTORS
		Margaret D. Farrell, Secretary

July 29, 2011

YOUR VOTE IS IMPORTANT!

         Whether or not you expect to attend the BancorpRI special meeting in person, BancorpRI urges you to submit your proxy as promptly as possible by accessing the internet website or calling the telephone number specified on the enclosed proxy card or by completing, signing and dating the enclosed proxy card and returning it in the enclosed postage-paid envelope. If your shares are held in the name of a bank, broker or other nominee, please follow the instructions on the voting instruction form furnished to you by your broker, bank or other nominee. Do not send your stock certificates with the proxy card. You will receive an election form with instructions for delivering your stock certificates under separate cover.

Table of Contents

ADDITIONAL INFORMATION

        The accompanying proxy statement/prospectus incorporates by reference important business and financial information about Brookline and BancorpRI from documents that are not included in or delivered with the proxy statement/prospectus. This information is available to you without charge upon your written or oral request. You can obtain the documents incorporated by reference in the proxy statement/prospectus by requesting them in writing or by telephone from the appropriate company at the following addresses and telephone numbers:

         If you would like to request documents, please do so by August 31, 2011 in order to receive them before the special meeting of BancorpRI shareholders.

        For a more detailed description of the information incorporated by reference in the accompanying proxy statement/prospectus and how you may obtain it, see the section of the proxy statement/prospectus titled "Where You Can Find More Information" beginning on page 119.

        The accompanying proxy statement/prospectus provides a detailed description of the merger and the merger agreement. We urge you to read the proxy statement/prospectus, including any documents incorporated by reference into the proxy statement/prospectus, and its annexes carefully and in their entirety. If you have any questions concerning the merger, the other meeting matters or the proxy statement/prospectus, or need assistance voting your shares, please contact BancorpRI's proxy solicitor at the address or telephone number listed below:

         Please do not send your stock certificates at this time. You will be sent separate instructions regarding the surrender of your stock certificates.

Table of Contents

TABLE OF CONTENTS

Table of Contents

Table of Contents

Table of Contents

QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE SPECIAL MEETING

        The following questions and answers are intended to address briefly some commonly asked questions regarding the merger and the special meeting. These questions and answers may not address all questions that may be important to you as a shareholder. To more fully understand the merger and the special meeting, you should read this entire proxy statement/prospectus, including the materials attached as annexes, as well as the documents that have been incorporated by reference into this proxy statement/prospectus.

        Unless the context otherwise requires, throughout this proxy statement/prospectus, "BancorpRI" refers collectively to Bancorp Rhode Island, Inc. and its subsidiaries; "BankRI" refers to Bank Rhode Island, a wholly-owned subsidiary of Bancorp Rhode Island, Inc.; "Brookline" refers to Brookline Bancorp, Inc. and its subsidiaries; and "we," "us" and "our" refer collectively to BancorpRI and Brookline. Also, we refer to the merger between BancorpRI and Brookline as the "merger" and the Agreement and Plan of Merger, dated as of April 19, 2011, by and between Brookline and BancorpRI as the "merger agreement."

Q:

Why am I receiving this proxy statement/prospectus?

A:

Brookline and BancorpRI have agreed to the acquisition of BancorpRI by Brookline under the terms of a merger agreement that is described in this proxy statement/prospectus. A copy of the merger agreement is attached to this proxy statement/prospectus as Annex A . In order to complete the merger, BancorpRI shareholders must vote to approve the merger agreement. BancorpRI will hold a special meeting of its shareholders to obtain this approval. This proxy statement/prospectus contains important information about the merger, the merger agreement, the special meeting of BancorpRI shareholders, and other related matters, and you should read it carefully. The enclosed voting materials for the special meeting allow you to vote your shares of BancorpRI common stock without attending the special meeting.

We are delivering this proxy statement/prospectus to you as both a proxy statement of BancorpRI and a prospectus of Brookline. It is a proxy statement because the BancorpRI board of directors is soliciting proxies from its shareholders to vote on the approval of the merger agreement at a special meeting of shareholders, and your proxy will be used at the special meeting or at any adjournment or postponement of the special meeting. It is a prospectus because Brookline will issue Brookline common stock to the BancorpRI shareholders who receive stock consideration in the merger, and this prospectus contains information about Brookline common stock.

Q:

What will happen in the merger?

A:

In the proposed merger, BancorpRI will merge with and into Brookline, with Brookline being the surviving corporation and BankRI becoming a wholly-owned subsidiary of Brookline.

Q:

What will I receive in the merger?

A:

If the merger agreement is approved and the merger is subsequently completed, each outstanding share of BancorpRI common stock will be converted into the right to receive either:

•

$48.25 in cash, without interest; or

•

4.686 shares of Brookline common stock,

in each case, subject to adjustment, election and allocation procedures specified in the merger agreement.

You may elect to receive all cash, all Brookline common stock, or a combination of both cash and Brookline common stock in exchange for your shares of BancorpRI common stock. However, the ability to receive all stock, all cash or a combination of each will depend on the elections of other BancorpRI shareholders. The allocation of the consideration payable to BancorpRI shareholders in

1

Table of Contents

the merger will not be known until Brookline tallies the results of the elections made by BancorpRI shareholders, which will not occur until immediately prior to the closing of the merger.

Q:

Will I receive the form of consideration I elect?

A:

The form of merger consideration you actually receive may differ from the form of consideration that you elect to receive. This is because the consideration to be received by each BancorpRI shareholder is subject to allocation procedures that are intended to ensure that 2,347,000 shares of BancorpRI common stock, or approximately 50% of the total number of shares of BancorpRI common stock outstanding immediately prior to the effective time of the merger, will be converted into shares of Brookline common stock, and the remaining shares of BancorpRI common stock will be converted into cash.

Q:

Will I receive any fractional share of Brookline common stock as part of the merger consideration?

A:

No. Brookline will not issue any fractional shares of Brookline common stock in the merger. Instead, Brookline will pay you the cash value of a fractional share measured by the average of the daily closing prices of Brookline common stock on The NASDAQ Stock Market, or NASDAQ, for the ten consecutive trading days ending on the fifth business day immediately prior to the closing date of the merger.

Q:

How do I make an election as to the form of merger consideration I wish to receive?

A:

No later than 20 business days prior to the anticipated closing date of the merger, we will mail to you an election form and letter of transmittal for the surrender of your BancorpRI stock certificates in exchange for the merger consideration. You will also receive detailed instructions describing the procedures you must follow to make your election. We will publicly announce the election deadline, which will be before the closing date of the merger. If you own shares of BancorpRI common stock in "street name" through a bank, broker or other nominee and you wish to make an election, you should seek instructions from the bank, broker or other nominee holding your shares concerning how to make an election.

We are not making any recommendation to you as to whether you should elect to receive cash, shares of Brookline common stock or a combination of each in the merger. You should evaluate your own specific circumstances and investment preferences in making your election.

Q:

Can I elect to receive my merger consideration in the form of cash with respect to a portion of my BancorpRI shares and Brookline common stock with respect to the rest of my BancorpRI shares?

A:

Yes. The election form and letter of transmittal will permit you, subject to the allocation procedures described in this proxy statement/prospectus, to receive at your election:

•

all of your merger consideration in the form of cash;

•

all of your merger consideration in the form of shares of Brookline common stock; or

•

a portion of your merger consideration in cash and the remaining portion in shares of Brookline common stock.

Q:

Do I have to return the election form and letter of transmittal?

A:

No, but if you do not do so by the election deadline, you will be allocated cash and/or shares of Brookline common stock depending entirely upon the elections made by other BancorpRI shareholders.

2

Table of Contents

Q:

What will happen to shares of Brookline common stock in the merger?

A:

Nothing. Each share of Brookline common stock outstanding will remain outstanding as a share of Brookline common stock.

Q:

What are the material federal income tax consequences of the merger to me?

A:

In general, if you exchange all of your shares of BancorpRI common stock for shares of Brookline common stock, you will not recognize either gain or loss for federal income tax purposes. If you exchange all of your shares of BancorpRI common stock for cash, you generally will recognize gain or loss for federal income tax purposes in an amount equal to the difference between the amount of cash received and your adjusted tax basis in your shares of BancorpRI common stock. If you exchange some or all of your shares of BancorpRI common stock for cash, you generally will recognize gain, but not loss, for federal income tax purposes in an amount equal to the lesser of (1) the amount of cash you receive in the merger, or (2) the amount, if any, by which the sum of the fair market value, as of the effective time of the merger, of any shares of Brookline common stock that you receive, and the amount of cash you receive in the merger, exceeds your adjusted tax basis in your shares of BancorpRI common stock. Generally, any gain recognized upon the exchange will be capital gain, and any such capital gain will be long-term capital gain if you have established a holding period of more than one year for your shares of BancorpRI common stock. Depending on certain facts specific to you, any gain could instead be characterized as ordinary dividend income.

This tax treatment may not apply to all BancorpRI shareholders. We strongly urge you to consult your own tax advisor for a full understanding of the tax consequences of the merger to you.

Q:

What are the conditions to completion of the merger?

A:

The obligations of Brookline and BancorpRI to complete the merger are subject to the satisfaction or waiver of certain closing conditions contained in the merger agreement, including the receipt of required regulatory approvals, tax opinions and approval of the merger agreement by BancorpRI shareholders.

Q:

When do you expect the merger to be completed?

A:

We will complete the merger when all of the conditions to completion contained in the merger agreement are satisfied or waived. Some of these conditions, such as the receipt of required regulatory approvals, are not entirely within our control. We currently expect to complete the merger during the fourth calendar quarter of 2011; however, because the merger is subject to these conditions, we cannot predict the actual timing.

Q:

What shareholder approvals are required to complete the merger?

A:

For BancorpRI, the affirmative vote of holders of at least a majority of the shares of BancorpRI common stock outstanding is required to approve the merger agreement. For Brookline, no approval of stockholders is needed and no vote will be taken.

Q:

Are there any shareholders already committed to voting in favor of the merger agreement?

A:

Yes. BancorpRI's directors and executive officers as of the date of the merger agreement, and certain of their affiliates, entered into voting agreements with Brookline requiring them to vote all of their shares in favor of approval of the merger agreement. These shareholders collectively held approximately 20.4% of the outstanding shares of BancorpRI common stock on the record date.

3

Table of Contents

Q:

When and where is the special meeting?

A:

The special meeting of shareholders of BancorpRI will be held at The Hotel Providence located at 311 Westminster Street, Providence, Rhode Island 02903, on Thursday, September 8, 2011 at 10:00 a.m., local time.

Q:

What will happen at the special meeting?

A:

At the special meeting, BancorpRI shareholders will consider and vote upon a proposal to approve the merger agreement and an advisory (non-binding) proposal to approve the golden parachute compensation payable to the named executive officers of BancorpRI in connection with the merger. If, at the time of the special meeting, there are not sufficient votes to approve the merger agreement, we may ask you to consider and vote upon a proposal to adjourn the special meeting, so that we can solicit additional proxies.

Q:

Who can vote at the special meeting?

A:

Holders of record of BancorpRI common stock at the close of business on July 27, 2011, which is the record date for the special meeting, are entitled to vote at the special meeting.

Q:

Does the BancorpRI board of directors recommend voting in favor of the merger agreement?

A:

Yes. After careful consideration, the BancorpRI board of directors unanimously recommends that BancorpRI shareholders vote "FOR" approval of the merger agreement. The BancorpRI board also recommends that shareholders vote " FOR " approval, on an advisory (non-binding) basis, of the golden parachute compensation payable to BancorpRI's named executive officers in connection with the merger, and " FOR " the adjournment proposal.

Q:

Are there any risks that I should consider in deciding whether to vote for approval of the merger agreement?

A:

Yes. You should read and carefully consider the risk factors set forth in the section of this proxy statement/prospectus titled "Risk Factors" beginning on page 24 as well as the other information contained in or incorporated by reference into this proxy statement/prospectus, including the matters addressed in the section of this proxy statement/prospectus titled "Special Note Regarding Forward-Looking Statements" on page 29.

Q:

Why am I being asked to cast an advisory (non-binding) vote to approve the golden parachute compensation payable to certain BancorpRI officers in connection with the merger?

A:

The Securities and Exchange Commission, in accordance with the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, recently adopted rules that require BancorpRI to seek an advisory (non-binding) vote with respect to certain payments that will or may be made to BancorpRI's named executive officers in connection with the merger.

Q:

What will happen if BancorpRI shareholders do not approve the golden parachute compensation at the special meeting?

A:

Approval of the golden parachute compensation payable in connection with the merger is not a condition to completion of the merger. The vote with respect to the golden parachute compensation is an advisory vote and will not be binding on BancorpRI regardless of whether the merger agreement is approved. Accordingly, as the compensation to be paid to the BancorpRI executives in connection with the merger is contractual, such compensation will or may be payable if the merger is completed regardless of the outcome of the advisory vote.

4

Table of Contents

Q:

How may I vote my shares for the special meeting proposals presented in this proxy statement/prospectus?

A:

You may vote by accessing the internet website or calling the telephone number specified on the proxy card or by completing, signing, dating and returning the proxy card in the enclosed postage-paid envelope as soon as possible. This will enable your shares to be represented and voted at the special meeting.

Q:

If my shares are held in "street name" by my broker, bank or other nominee, will my broker, bank or other nominee automatically vote my shares for me?

A:

No. Your broker, bank or other nominee will not vote your shares unless you provide instructions to your broker, bank or other nominee on how to vote. It is important that you provide timely instruction to your broker or bank to ensure that all shares of BancorpRI common stock that you own are voted at the special meeting. You should fill out the voter instruction form sent to you by your broker, bank or other nominee with this proxy statement/prospectus.

Q:

What if I fail to return my proxy card or to instruct my broker, bank or other nominee to vote my shares?

A:

If you fail to return your proxy card or to instruct your broker, bank or other nominee to vote your shares, your shares will not be voted. This will have the same effect as a vote against approval of the merger agreement, but will have no impact on the outcome of the other proposals.

Q:

What do I need to do now?

A:

You should carefully read and consider the information contained or incorporated by reference into this proxy statement/prospectus, including its annexes. This proxy statement/prospectus contains important information about the merger, the merger agreement, Brookline and BancorpRI, including the historical and pro forma financial information set forth in the sections of this proxy statement/prospectus titled "Selected Historical Financial Data for Brookline and BancorpRI" and "Unaudited Pro Forma Combined Condensed Consolidated Financial Information Relating to the Ipswich and BancorpRI Mergers" beginning on pages 18 and 109, respectively. After you have read and considered this information, BancorpRI shareholders are requested to vote by mail, by telephone, through the internet or by attending the special meeting and voting in person. If you choose to vote by mail, you should complete, sign and date your proxy card and return it in the enclosed postage-paid return envelope as soon as possible so that your shares of BancorpRI common stock will be represented and voted at the special meeting. The proxy card will instruct the persons named on the proxy card to vote your shares at the special meeting as you direct. If you sign and send in a proxy card and do not indicate how you wish to vote, the proxy will be voted " FOR " all of the special meeting proposals.

Q:

What should I do if I receive more than one set of voting materials?

A:

You may receive more than one set of voting materials, including multiple copies of this proxy statement/prospectus and multiple BancorpRI proxy cards or voting instruction cards. For example, if you hold your BancorpRI shares in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold BancorpRI shares. Please complete, sign, date and return each proxy card and voting instruction card that you receive, or otherwise follow the voting instructions set forth on the proxy card and voting instruction card.

Q:

Can I attend the special meeting and vote my shares in person?

A:

Yes. Although the BancorpRI board of directors requests that you vote your shares by mail, by telephone, or through the internet in advance of the special meeting, all BancorpRI shareholders

5

Table of Contents

are invited to attend the special meeting. Shareholders of record on July 27, 2011 may vote in person at the special meeting. If your shares are held by a broker, bank or other nominee, then you are not the shareholder of record and you must bring to the special meeting appropriate documentation from your broker, bank or other nominee to enable you to vote at the special meeting.

Q:

Can I change my vote after I have submitted a proxy?

A:

Yes. If you do not hold your shares in "street name," there are three ways you can change your vote at any time after you have sent in your proxy card and before your proxy is voted at the special meeting:

•

You may file a written revocation of the proxy with the Secretary of BancorpRI, Margaret D. Farrell, c/o Hinckley, Allen & Snyder LLP, 50 Kennedy Plaza, Suite 1500, Providence, Rhode Island 02903;

•

You may submit a new signed proxy card bearing a later date or vote again by telephone or internet (any earlier proxies will be revoked automatically); or

•

You may attend the special meeting and vote in person provided that you are the holder of record of your shares and have filed a written revocation of your grant of proxy with the Secretary of BancorpRI as indicated above.

If you hold your shares in "street name" and have instructed a bank, broker or other nominee to vote your shares, you must follow the directions you receive from your bank, broker or other nominee to change your vote.

Q:

What happens if I sell my shares after the record date but before the special meeting?

A:

The record date of the special meeting is earlier than both the date of the special meeting and the date that the merger is expected to be completed. If you sell or otherwise transfer your BancorpRI shares after the record date but before the date of the special meeting, you will retain your right to vote at the special meeting, but you will transfer the right to receive the merger consideration to the person to whom you transferred your shares. In order to receive the merger consideration, you must hold your shares through completion of the merger.

Q:

Do I have the right to dissent and obtain the fair market value of my shares?

A:

No. Under Rhode Island corporate law, BancorpRI shareholders who object to the merger do not have any appraisal or dissenters' rights.

Q:

Should I send in my stock certificates now?

A:

No. You will receive separate written instructions for making your election of all cash, all Brookline common stock or a combination of each, and for surrendering your shares of BancorpRI common stock in exchange for the merger consideration. In the meantime, you should retain your stock certificate(s) because they are still valid. Please do not send in your stock certificate(s) with your proxy card.

Q:

Whom should I call with questions?

A:

If you have questions about the merger or the special meeting, or if you need additional copies of this proxy statement/prospectus or the enclosed proxy card, you should contact BancorpRI's proxy solicitor, Phoenix Advisory Partners, at (877) 478-5038.

Q:

Where can I find more information about the companies?

A:

You can find more information about Brookline and BancorpRI from the various sources described in the section of this proxy statement/prospectus titled "Where You Can Find More Information" beginning on page 119.

6

Table of Contents

SUMMARY

        This summary highlights selected information from this proxy statement/prospectus and may not contain all of the information that is important to you. To more fully understand the merger and for a more complete description of the legal terms of the merger, you should read this entire document, including the materials attached as annexes, as well as the other documents to which we have referred you. See the section of this proxy statement/prospectus titled "Where You Can Find More Information" beginning on page 119. The page references in parentheses included in this summary will direct you to a more detailed description of each topic presented.

The Companies

Brookline Bancorp, Inc. (page 30)

        Brookline is a Delaware corporation organized in 1997 that serves as the holding company for Brookline Bank, a federally-chartered thrift established in 1871, and The First National Bank of Ipswich, a national bank founded in 1892 and acquired by Brookline in February 2011. Brookline also holds an approximately 85% ownership interest in Eastern Funding LLC, which specializes primarily in the financing of coin-operated laundry, dry cleaning and convenience store equipment and businesses in the greater New York/New Jersey metropolitan area and in other locations throughout the United States.

        The principal business of Brookline and its subsidiaries is to accept consumer and commercial deposits, originate loans to individuals and commercial businesses, and to provide cash management and investment advisory services.

        At March 31, 2011, Brookline had total consolidated assets of approximately $3.1 billion, loans of approximately $2.5 billion, deposits of approximately $2.1 billion and stockholders' equity of approximately $497.6 million.

        Brookline's principal executive offices are located at 160 Washington Street, Brookline, Massachusetts 02445, and its telephone number is (617) 730-3500.

Bancorp Rhode Island, Inc. (page 30)

        BancorpRI, a Rhode Island corporation, is the holding company for BankRI. BancorpRI has no significant assets other than the common stock of BankRI. BankRI has four wholly-owned subsidiaries, which include BRI Investment Corp., a Rhode Island passive investment company, Macrolease Corporation, an equipment financing company, Acorn Insurance Agency, Inc., a licensed insurance agency, and BRI Realty Corp., a real estate holding company.

        BankRI is a commercial bank chartered as a financial institution in the State of Rhode Island that was formed in 1996 as a result of the acquisition of certain assets and liabilities divested in connection with the merger of Fleet Financial Group, Inc. and Shawmut National Corporation. BankRI offers its customers a wide range of business, commercial real estate, consumer and residential loans, commercial leases, deposit products, nondeposit investment products, cash management and online banking services, private banking and other banking products and services designed to meet the financial needs of individuals and small to mid-sized businesses.

        At March 31, 2011, BancorpRI had total consolidated assets of approximately $1.6 billion, loans of approximately $1.2 billion, deposits of approximately $1.1 billion and shareholders' equity of approximately $130.2 million.

        BancorpRI's principal executive offices are located at One Turks Head Place, Providence, Rhode Island 02903, and its telephone number is (401) 456-5000.

7

Table of Contents

The Special Meeting of BancorpRI Shareholders

Date, Time and Place of the Special Meeting (page 31)

        The special meeting of shareholders of BancorpRI will be held at The Hotel Providence, 311 Westminster Street, Providence, Rhode Island 02903, on Thursday, September 8, 2011 at 10:00 a.m., local time.

Actions to be Taken at the Special Meeting (page 31)

        At the special meeting, BancorpRI's shareholders as of July 27, 2011, the record date, will be asked to vote upon a proposal to approve the merger agreement with Brookline, a proposal to approve, on an advisory (non-binding) basis, the golden parachute compensation payable to the named executive officers of BancorpRI in connection with the merger and, if necessary, a proposal to approve one or more adjournments of the special meeting.

Recommendation of BancorpRI Board of Directors (page 31)

        At a meeting on April 19, 2011, the BancorpRI board of directors determined that the merger is fair to and in the best interests of BancorpRI and its shareholders, and unanimously approved the merger agreement. The BancorpRI board unanimously recommends that you vote "FOR" approval of the merger agreement, " FOR " approval, on an advisory (non-binding) basis, of the golden parachute compensation payable to the named executive officers of BancorpRI in connection with the merger, and " FOR " approval of the proposal to adjourn the special meeting.

Record Date; Outstanding Shares; Shares Entitled to Vote (page 31)

        Only holders of record of BancorpRI common stock at the close of business on the record date of July 27, 2011 are entitled to notice of and to vote at the special meeting. As of the record date, there were 4,684,705 shares of BancorpRI common stock outstanding, held of record by approximately 88 shareholders.

Quorum; Vote Required (page 31)

        A quorum of BancorpRI shareholders is necessary to hold a valid meeting. If the holders of at least a majority of the total number of the outstanding shares of BancorpRI common stock entitled to vote are represented in person or by proxy at the special meeting, a quorum will exist. BancorpRI will include proxies marked as abstentions in determining the presence of a quorum at the special meeting.

        The affirmative vote of the holders of at least a majority of the outstanding shares of BancorpRI common stock is required to approve the merger agreement. The affirmative vote of holders of a majority of BancorpRI common stock present in person or represented by proxy at the special meeting is required to approve (1) on an advisory (non-binding) basis, BancorpRI's golden parachute compensation payable to the named executive officers of BancorpRI in connection with the merger, and (2) the proposal to adjourn the special meeting.

Share Ownership of Management; Voting Agreements (page 91)

        In connection with the merger agreement, BancorpRI's directors and executive officers and certain of their affiliates executed voting agreements with Brookline under which they agreed to vote their shares in favor of the merger agreement and granted Brookline an irrevocable proxy to so vote their shares. Following execution of the voting agreements, on June 23, 2011, Malcolm G. Chace, Chairman of the BancorpRI board of directors, passed away. Any successors to the shares of BancorpRI common stock held by Mr. Chace will continue to be bound by the terms of the voting agreements. As of the record date, there were 955,785 shares of BancorpRI common stock, or approximately 20.4% of the outstanding shares, subject to the voting agreements. These shares included 368,504 shares of

8

Table of Contents

BancorpRI common stock, or approximately 7.9% of the outstanding shares as of the record date, that are held by current directors and executive officers of BancorpRI.

Proxies, Voting and Revocation (page 32)

        The BancorpRI board of directors requests that you vote your shares by telephone, through the internet or by returning the proxy card accompanying this proxy statement/prospectus. If you choose to vote by mail, please complete, date and sign the proxy card and promptly return it in the enclosed pre-paid envelope. All properly signed proxies received prior to the special meeting and not revoked before the vote at the special meeting will be voted at the special meeting according to the instructions indicated on the proxies or, if no instructions are given, to approve the merger agreement, the advisory proposal regarding the golden parachute compensation payable to BancorpRI's named executive officers in connection with the merger, and the adjournment proposal. If you fail to submit a proxy or to vote in person at the special meeting, or do not provide your broker, bank or other nominee with instructions, as applicable, your shares of BancorpRI common stock will not be voted on the proposals, which will have the same effect as a vote " AGAINST " the proposal to approve the merger agreement, but will have no effect on the other proposals.

        If you have not voted through your broker, bank or other nominee, you may revoke your proxy at any time by taking any of the following actions before your proxy is voted at the special meeting:

•

Filing a written revocation of the proxy with the Secretary of BancorpRI, Margaret D. Farrell, c/o Hinckley, Allen & Snyder LLP, 50 Kennedy Plaza, Suite 1500, Providence, Rhode Island 02903;



•

Submitting a new signed proxy card bearing a later date or voting again by telephone or internet (any earlier proxies will be revoked automatically); or



•

Attending and voting in person at the special meeting provided you are the holder of record of your shares and have filed a written revocation of your grant of proxy with the Secretary of BancorpRI as indicated above.

        If you have instructed a bank, broker or other nominee to vote your shares, you must follow the directions you receive from your bank, broker or other nominee to change your vote.

No Dissenters' Rights (page 34)

        BancorpRI is organized as a corporation under Rhode Island law. Under Rhode Island corporate law, BancorpRI shareholders who object to the merger do not have any appraisal or dissenters' rights.

The Merger

Structure of the Merger (page 68)

        Brookline and BancorpRI entered into an Agreement and Plan of Merger on April 19, 2011. The merger agreement provides for the merger of BancorpRI with and into Brookline, with Brookline being the surviving corporation and BankRI becoming a wholly-owned subsidiary of Brookline.

        The proposed merger will occur following approval of the proposal regarding the merger agreement described in this proxy statement/prospectus by the shareholders of BancorpRI and satisfaction or waiver of all other conditions to the merger. The merger agreement is attached to this document as Annex A . We encourage you to read the merger agreement because it is the legal document that governs the merger.

Merger Consideration (page 68)

        If the merger is completed, each share of BancorpRI common stock will be converted into the right to receive either:

•

$48.25 in cash, without interest (which is referred to as the cash consideration); or

9

Table of Contents

•

4.686 shares of Brookline common stock, plus cash in lieu of any fractional share (which is referred to as the stock consideration).

        You will have the opportunity to elect the form of consideration that you receive in the merger in exchange for your shares of BancorpRI common stock. You may elect to receive all of your merger consideration in cash or Brookline common stock, or a portion of your merger consideration in cash and the remaining portion in shares of Brookline common stock. However, your right to receive the form of consideration that you elect for your shares will be subject to allocation and proration procedures set forth in the merger agreement. These allocation and proration procedures are intended to ensure that 2,347,000 shares of BancorpRI common stock, or approximately 50% of the total number of shares of BancorpRI common stock outstanding immediately prior to the effective time of the merger, will be converted into shares of Brookline common stock, and the remaining shares of BancorpRI common stock will be converted into cash.

        No fractional shares of Brookline common stock will be issued in connection with the merger. Instead, each BancorpRI shareholder will receive an amount of cash, in lieu of any fractional share, based on the average per share closing price of Brookline common stock on NASDAQ for the ten consecutive trading days ending on the fifth business day immediately prior to the closing date of the merger, rounded to the nearest whole cent.

Election Procedures (page 69)

        The shares of BancorpRI common stock that you hold will be exchanged for cash, Brookline common stock or a combination of cash and Brookline common stock as chosen by you, subject to the allocation and proration procedures described in the merger agreement. No less than 20 business days prior to the anticipated closing date of the merger, you will be sent an election form and detailed instructions to permit you to choose your preferred consideration. You have the following choices:

•

you may elect to receive $48.25 per share in cash, without interest, in exchange for all shares of BancorpRI common stock that you hold;



•

you may elect to receive 4.686 shares of Brookline common stock in exchange for all shares of BancorpRI common stock that you hold, plus cash in lieu of any fractional share;



•

you may elect to receive the cash consideration with respect to a portion of the shares of BancorpRI common stock that you hold, and the stock consideration with respect to your remaining shares; or



•

you may make no election with respect to the consideration to be received by you in exchange for your shares of BancorpRI common stock.

        You will have a limited period of time in which to complete the election form and return it as instructed. In order to be effective, a properly completed election form must be received by the exchange agent on or before 5:00 p.m., Eastern time, on the 25th day following the mailing date of the election form to BancorpRI shareholders, unless Brookline and BancorpRI have mutually agreed to another date and time as the election deadline, which date will be at least five business days prior to the anticipated closing date of the merger and publicly announced by Brookline as soon as practicable prior to the election deadline. You will need to surrender your BancorpRI stock certificates to receive the appropriate consideration, but you should not send us any certificates now. You will receive detailed instructions on how to exchange your stock certificates along with your election form. If you do not submit an election form, you will receive instructions on where to surrender your BancorpRI stock certificates after the merger is completed.

        If your shares or a portion of your shares of BancorpRI common stock are held in "street name" by a broker, bank or other nominee, an election form will be mailed to the broker, bank or other nominee with respect to those shares.

10

Table of Contents

        If you hold a portion of your shares in an individual retirement account and the remaining portion of your shares is held directly in your name, you will receive two election forms: one for your shares held in the individual retirement account and one for the shares held directly in your name.

Allocation Procedures (page 70)

        The merger agreement provides for overall limitations on the amount of cash and shares of Brookline common stock available in the merger as follows:

•

2,347,000 shares of BancorpRI common stock, or approximately 50% of the total number of shares of BancorpRI common stock outstanding immediately prior to the effective time of the merger, will be converted into the right to receive the stock consideration; and



•

the remaining shares of BancorpRI common stock will be converted into the right to receive the cash consideration.

        As a result, whether you receive the amount of cash and/or stock you request in your election form will depend in part on the elections of other BancorpRI shareholders. You may not receive the form of consideration that you elect in the merger, and you may instead receive a pro rata amount of cash and Brookline common stock.

        If you have a preference for receiving either cash or Brookline common stock for your shares of BancorpRI common stock, you should return the election form indicating your preference. BancorpRI shareholders who make an election will be accorded priority over those shareholders who make no election in instances where the cash consideration or stock consideration must be re-allocated in order to achieve the required ratio of BancorpRI shares being converted into the right to receive cash and Brookline common stock. If you do not make an election, you will be allocated cash and/or Brookline common stock depending on the elections made by other BancorpRI shareholders. Please see the examples set forth in the section of this proxy statement/prospectus titled "The Merger Agreement—Allocation Procedures" beginning on page 70. However, even if you do make an election, the form of merger consideration you actually receive may differ from the form of merger consideration you elect to receive.

        The market price of Brookline common stock will fluctuate between the date of this proxy statement/prospectus, the date of your election and the effective time of the merger. Because the exchange ratio is fixed, such fluctuations will alter the value of the shares of Brookline common stock that you may receive in the merger. In addition, because the tax consequences of receiving cash will differ from the tax consequences of receiving Brookline common stock, you should carefully read the section of this proxy statement/prospectus titled "Material Federal Income Tax Consequences" beginning on page 93.

Treatment of BancorpRI Equity Awards (page 75)

        At the effective time of the merger, BancorpRI will terminate its equity plans. Each option granted under BancorpRI's equity plans, whether vested or unvested, which is outstanding immediately prior to the effective time of the merger and which has not been previously exercised or cancelled, will be cancelled at the effective time of the merger. In exchange for the cancellation of an option, the holder of that option will be entitled to receive a cash payment from BancorpRI in an amount equal to the product of:

•

the number of BancorpRI shares provided for in the option; and



•

the excess, if any, of $48.25 over the exercise price per share provided in the option.

        At the effective time of the merger, each restricted stock award granted under BancorpRI's equity plans will vest in full and no longer be subject to any forfeiture or vesting requirements, and all such shares of BancorpRI common stock will be considered outstanding shares whose holders will be entitled to receive election forms and to receive the merger consideration.

11

Table of Contents

        At the effective time of the merger, each performance share award granted to any BancorpRI employee under BancorpRI's equity plans will be cancelled. In exchange for the cancellation of a performance share award, the holder of that performance share award will be entitled to receive a cash payment from BancorpRI in an amount equal to the product of:

•

$48.25; and



•

the number of performance shares earned in accordance with the terms governing such award as of the effective time of the merger, based on performance calculated through the last day of the calendar quarter ending immediately prior to the closing of the merger. For purposes of determining whether performance shares have been earned, BancorpRI's earnings per share will be calculated without deducting any merger-related expenses, including any expenses resulting from the acceleration of the vesting of equity awards.

        At the effective time of the merger, each restricted stock unit award granted to each non-employee director under BancorpRI's equity plans will vest in full and no longer be subject to any forfeiture or vesting requirements, and the holder of that restricted stock unit award will be entitled to receive a cash payment from BancorpRI in an amount equal to the product of:

•

$48.25; and



•

the number of restricted stock units provided in the restricted stock unit award.

Opinion of BancorpRI's Financial Advisor (page 42)

        In connection with the merger, BancorpRI's board of directors received an opinion from BancorpRI's financial advisor, Jefferies & Company, Inc., or Jefferies, dated April 19, 2011, as to the fairness, from a financial point of view and as of such date, of the merger consideration to be received by holders of BancorpRI common stock. The full text of Jefferies' opinion describes the assumptions made, procedures followed, matters considered and limitations on the review undertaken by Jefferies. This opinion is attached as Annex C and is incorporated into this proxy statement/prospectus by reference. Jefferies' opinion was provided for the use and benefit of the BancorpRI board of directors (in its capacity as such) in its evaluation of the merger consideration from a financial point of view and did not address any other aspect of the merger. The opinion did not address the relative merits of the transactions contemplated by the merger agreement as compared to any alternative transactions or opportunity that might be available to BancorpRI, nor did it address BancorpRI's underlying business decision to engage in the merger or the terms of the merger agreement or the documents referred to in the merger agreement. Jefferies' opinion does not constitute a recommendation to any shareholder as to any election to be made by such shareholder with respect to the merger consideration or how any shareholder should vote or act with respect to the merger or any related matter. Jefferies' opinion was based on economic, monetary, regulatory, market and other conditions existing and which could be evaluated as of the date of Jefferies' opinion. Jefferies expressly disclaimed any undertaking or obligation to advise any person of any change in any fact or matter affecting its opinion of which Jefferies becomes aware after the date of the opinion.

Interests of BancorpRI Directors and Executive Officers in the Merger (page 54)

        Some of the members of BancorpRI's management and board of directors may be deemed to have interests in the merger that are different from, or in addition to, the interests of BancorpRI shareholders generally. These interests include:

•

payment of cash severance benefits under existing employment agreements with BancorpRI's executive officers upon a terminating event, with continued health, dental, life and accident insurance coverage for a period of 24 to 36 months;



•

vesting of the benefits of the executives under the BankRI supplemental executive retirement plan;

12

Table of Contents

•

acceleration of vesting of all unvested equity awards held by the executives;



•

payment with respect to outstanding performance share awards held by the executives and restricted stock units held by directors based on a per share price of $48.25;



•

continued indemnification and liability insurance coverage for directors and executive officers with respect to acts or omissions occurring before the merger; and



•

election of Merrill W. Sherman and another BancorpRI director to the Brookline board of directors upon completion of the merger, and continuing service of the current BankRI directors (other than Ms. Sherman) on the BankRI board.

        Also at the closing of the merger, Ms. Sherman will retire from BancorpRI and BankRI. In connection with her retirement, Brookline, BancorpRI and BankRI have entered into a release, consulting and non-competition agreement with Ms. Sherman, which will be effective upon the closing of the merger. Under this agreement, Ms. Sherman will provide consulting services to Brookline for a period of one year following the closing, and will be subject to certain non-competition and non-solicitation covenants for a period of two years following the closing. In addition, Brookline entered into an employment letter agreement with Mark J. Meiklejohn, currently BankRI's Executive Vice President and Chief Lending Officer, under which Mr. Meiklejohn will be employed as President and Chief Executive Officer of BankRI following the merger. The BancorpRI board of directors was aware of these interests and considered them in recommending that BancorpRI shareholders approve the merger agreement.

Limitations on Considering Other Acquisition Proposals (page 80)

        The merger agreement restricts BancorpRI's ability to solicit or engage in discussions or negotiations with a third party regarding a proposal to acquire a significant interest in BancorpRI. However, if BancorpRI receives a bona fide unsolicited written acquisition proposal from a third party that is, or is reasonably likely to be, more favorable to BancorpRI shareholders than the terms of the merger agreement, BancorpRI may furnish nonpublic information to that third party and engage in negotiations regarding an acquisition proposal with that third party, subject to specified conditions in the merger agreement. In addition, the BancorpRI board of directors may not:

•

modify, qualify, withhold or withdraw its approval or recommendation of the merger agreement;



•

approve or recommend another acquisition proposal to its shareholders; or



•

cause BancorpRI to enter into a letter of intent or definitive agreement with respect to an acquisition transaction or that requires BancorpRI to abandon, terminate or fail to consummate the merger,

unless the BancorpRI board of directors determines in good faith, after consultation with counsel and a financial advisor, that an acquisition proposal is a superior proposal and, after consultation with counsel, that it is required to take such action to comply with its fiduciary duties to shareholders under applicable law. In that event, BancorpRI must provide Brookline with notice of such determination and cooperate and negotiate in good faith with Brookline to adjust or modify the terms and conditions of the merger agreement.

Conditions to the Merger (page 76)

        Brookline and BancorpRI will not complete the merger unless a number of conditions are satisfied or waived, including:

•

the shareholders of BancorpRI must approve the merger agreement;



•

Brookline and BancorpRI must have obtained all regulatory approvals required to complete the transactions contemplated by the merger agreement, all related statutory waiting periods have expired, and none of the regulatory approvals imposed any term, condition or restriction that

13

Table of Contents

Brookline reasonably determines would prohibit or materially limit the ownership or operation by BancorpRI or Brookline of all or any material portion of the business or assets of BancorpRI or Brookline, or compel Brookline to dispose of or hold separate all or any material portion of the business or assets of BancorpRI or Brookline (a so-called "burdensome condition");

•

the absence of any order, decree or injunction in effect, or any law, statute or regulation enacted or adopted, that enjoins, prohibits, materially restricts or makes illegal the completion of the transactions contemplated by the merger agreement;



•

Brookline and BancorpRI must each receive a legal opinion from their respective counsel regarding treatment of the merger as a "reorganization" for federal income tax purposes;



•

the representations and warranties of each of Brookline and BancorpRI in the merger agreement must be accurate, subject to exceptions that would not have a material adverse effect;



•

Brookline and BancorpRI must each have performed in all material respects all obligations required to be performed by it; and



•

no event or development must have occurred with respect to BancorpRI or Brookline that has had, or would reasonably be expected to have, a material adverse effect.

Termination of the Merger Agreement (page 77)

        Brookline and BancorpRI can mutually agree to terminate the merger agreement before the merger has been completed, and either company can terminate the merger agreement if:

•

the merger is not consummated by March 31, 2012, unless the terminating party's failure to comply with the merger agreement was the cause of the failure of the merger to occur on or before this date;



•

the other party materially breaches any of its representations, warranties, covenants or agreements contained in the merger agreement, the terminating party is not then in material breach of any representation, warranty, covenant or other agreement contained in the merger agreement, and the breach is not cured within 30 days of written notice;



•

any regulatory approval required for consummation of the merger and the other transactions contemplated by the merger agreement has been denied by final nonappealable action of any regulatory authority, or any governmental entity has issued a final nonappealable order, injunction or decree enjoining or otherwise prohibiting the transactions contemplated by the merger agreement, and the terminating party has used its reasonable best efforts to have the order, injunction or decree lifted; or



•

the required approval of the merger agreement by the BancorpRI shareholders is not obtained.

        In addition, Brookline may terminate the merger agreement if:

•

the BancorpRI board of directors:



•

withdraws, qualifies, amends, modifies or withholds its recommendation to the BancorpRI shareholders to vote in favor of the merger agreement or makes any statement, filing or release that is inconsistent with the recommendation;



•

materially breaches its obligation to call, give notice of and commence the special meeting;



•

approves or recommends another acquisition proposal;



•

fails to publicly recommend against a publicly announced acquisition proposal within five business days of being requested to do so by Brookline;



•

fails to publicly reconfirm its recommendation to its shareholders to vote in favor of the merger agreement within five business days of being requested to do so by Brookline; or

14

Table of Contents

•

resolves or otherwise determines to take, or announces an intention to take, any of the actions listed above; or



•

BancorpRI breaches in any material respect the provisions in the merger agreement prohibiting the solicitation of other offers.

        BancorpRI has the right to terminate the merger agreement in connection with entering into a definitive agreement to effect a superior proposal, subject to specified conditions in the merger agreement. In addition, BancorpRI has the right to terminate the merger agreement if the average closing price of Brookline common stock for a specified period prior to closing is less than $8.278 and Brookline common stock underperforms a specified peer-group index by more than 20%, provided that Brookline will have the option to increase the amount of Brookline common stock to be provided to BancorpRI shareholders, in which case no termination will occur.

Termination Fee (page 79)

        Under the terms of the merger agreement, BancorpRI must pay Brookline a termination fee of $8.9 million if:

•

Brookline terminates the merger agreement as a result of the BancorpRI board of directors:



•

withdrawing, qualifying, amending, modifying or withholding its recommendation to the BancorpRI shareholders to vote in favor of the merger agreement or making any statement, filing or release that is inconsistent with the recommendation;



•

materially breaching its obligation to call, give notice of and commence the special meeting;



•

approving or recommending another acquisition proposal;



•

failing to publicly recommend against a publicly announced acquisition proposal within five business days of being requested to do so by Brookline;



•

failing to publicly reconfirm its recommendation to its shareholders to vote in favor of the merger agreement within five business days of being requested to do so by Brookline; or



•

resolving or otherwise determining to take, or announcing an intention to take, any of the actions listed above;



•

Brookline terminates the merger agreement as a result of a material breach by BancorpRI of the provisions in the merger agreement prohibiting the solicitation of other offers;



•

BancorpRI terminates the merger agreement in connection with entering into a definitive agreement to effect a superior proposal;



•

Brookline or BancorpRI terminates the merger agreement as a result of:



•

the failure of the BancorpRI shareholders to approve the merger agreement, or the merger not having been consummated by March 31, 2012 due to the failure of the BancorpRI shareholders to approve the merger agreement, and both



•

an acquisition proposal with respect to BancorpRI has been publicly announced, disclosed or otherwise communicated to the BancorpRI board of directors or senior management of BancorpRI prior to the special meeting or March 31, 2012, as applicable; and



•

within 12 months of termination of the merger agreement, BancorpRI recommends to its shareholders another acquisition proposal or enters into a definitive agreement with respect to, or consummates, another acquisition transaction; or

15

Table of Contents

•

Brookline terminates the merger agreement as a result of a material breach by BancorpRI of any of its representations, warranties, covenants or agreements contained in the merger agreement, if both:



•

an acquisition proposal with respect to BancorpRI has been publicly announced, disclosed or otherwise communicated to the BancorpRI board of directors or senior management of BancorpRI prior to such breach or during the related cure period; and



•

within 12 months of termination of the merger agreement, BancorpRI recommends to its shareholders another acquisition proposal or enters into a definitive agreement with respect to, or consummates, another acquisition transaction.

Effective Time of the Merger (page 68)

        We expect that the merger will be completed as soon as practicable following the satisfaction or waiver of all closing conditions, including approval of the merger agreement by the BancorpRI shareholders at the special meeting and receipt of all regulatory approvals. The parties cannot be certain whether or when any of the conditions to the merger will be satisfied or waived, where permissible. We currently expect to complete the merger during the fourth calendar quarter of 2011; however, because the merger is subject to these conditions, we cannot predict the actual timing.

Material Federal Income Tax Consequences (page 93)

        Each of Brookline and BancorpRI will receive an opinion of counsel to the effect that, based on certain facts, representations and assumptions, the merger will be treated as a "reorganization" for federal income tax purposes. Accordingly, you generally will not recognize any gain or loss on the conversion of shares of BancorpRI common stock solely into shares of Brookline common stock. However, you generally will be taxed if you receive cash in exchange for your shares of BancorpRI common stock or instead of any fractional share of Brookline common stock that you would otherwise be entitled to receive. Each of Brookline's and BancorpRI's obligations to complete the merger are conditioned on its receipt of this opinion, dated as of the effective date of the merger, regarding the federal income tax treatment of the merger to it and the shareholders of BancorpRI.

        Tax matters are complicated, and the tax consequences of the merger to you will depend upon the facts of your particular situation and on whether you receive stock, cash or a mix of stock and cash in the merger. In addition, you may be subject to state, local or foreign tax laws that are not discussed in this proxy statement/prospectus. Accordingly, we strongly urge you to consult your own tax advisor for a full understanding of the tax consequences to you of the merger.

Required Regulatory Approvals (page 89)

        To complete the merger, Brookline and BancorpRI need the prior approval of the Board of Governors of the Federal Reserve System and certain state regulatory authorities. The United States Department of Justice is able to provide input into the approval process of federal banking agencies to challenge the approval on antitrust grounds. Prior to the special meeting date, Brookline and BancorpRI will have filed all necessary applications and notices with the applicable regulatory authorities. Brookline and BancorpRI cannot predict, however, whether or when the required regulatory approvals will be obtained or whether any such approvals will impose any burdensome condition upon Brookline.

Accounting Treatment (page 51)

        The merger will be accounted for using the acquisition method of accounting with Brookline treated as the acquiror. Under this method of accounting, BancorpRI's assets and liabilities will be recorded by Brookline at their respective fair values as of the closing date of the merger and added to those of Brookline. Any excess of purchase price over the net fair values of BancorpRI's assets and

16

Table of Contents

liabilities will be recorded as goodwill. Any excess of the fair value of BancorpRI's net assets over the purchase price will be recognized in earnings by Brookline on the closing date of the merger. Financial statements of Brookline issued after the merger will reflect these values, but will not be restated retroactively to reflect the historical financial position or results of operations of BancorpRI prior to the merger. The results of operations of BancorpRI will be included in the results of operations of Brookline beginning on the day after the effective date of the merger.

Listing of Brookline Common Stock to be Issued in the Merger (page 51)

        Brookline's common stock is quoted on the NASDAQ Global Select Market under the trading symbol "BRKL." Under the terms of the merger agreement, to the extent required by NASDAQ, Brookline will file a notice of additional listing of shares with NASDAQ with respect to the shares of Brookline common stock to be issued to the holders of BancorpRI common stock in the merger, and will use its reasonable best efforts to cause such shares to be approved for quotation on NASDAQ.

Differences Between Rights of Holders of Brookline and BancorpRI Stock (page 96)

        The rights of BancorpRI shareholders currently are governed by BancorpRI's articles of incorporation and bylaws, and by Rhode Island law. After the merger is completed, BancorpRI shareholders who receive Brookline common stock in the merger will become stockholders of Brookline, and, therefore, their rights as stockholders of Brookline will be governed by Brookline's certificate of incorporation and bylaws, and by Delaware law. This means that, as a result of the merger, BancorpRI shareholders will have different rights when they become holders of Brookline common stock than they currently have as holders of BancorpRI common stock.

Recent Developments

        On July 20, 2011, Brookline announced earnings for the quarter ended June 30, 2011 of $7.0 million, or $0.119 per share on a basic and diluted basis, as compared to $7.1 million, or $0.121 per share on a basic and diluted basis, for the quarter ended June 30, 2010. Net income for the 2011 second quarter was reduced by $774,000 ($0.013 per share) as a result of non-tax deductible professional fees incurred relating to acquisition transactions. Net income for the first half of 2011 was $14.3 million, or $0.243 per share on a basic and diluted basis, as compared to $13.4 million, or $0.229 per share on a basic and diluted basis, for the first half of 2010. Net income for the 2011 first half was reduced by $924,000 ($0.016 per share) as a result of non-tax deductible professional fees incurred relating to acquisition transactions. At June 30, 2011, Brookline had total assets of $3.1 billion, loans of $2.6 billion, deposits of $2.2 billion, borrowings of $426.1 million and stockholders' equity of $501.1 million. In addition, Brookline announced its quarterly dividend of $0.085 per share, which will be paid on August 17, 2011 to stockholders of record on August 1, 2011.

        On July 21, 2011, BancorpRI announced earnings for the quarter ended June 30, 2011 of $1.8 million, or $0.38 per share on a diluted basis, as compared to $2.7 million, or $0.57 per share on a diluted basis, for the quarter ended June 30, 2010. Net income for the first half of 2011 was $4.1 million, or $0.87 per share on a diluted basis, as compared to net income of $4.9 million, or $1.05 per share on a diluted basis, for the first half of 2010. These results reflect expenses of $1.5 million on an after-tax basis, or $0.32 per share, in the 2011 second quarter related to the pending merger with Brookline. At June 30, 2011, BancorpRI had total assets of $1.6 billion, loans and leases of $1.2 billion, deposits of $1.1 billion, borrowings of $362.6 million and shareholders' equity of $133.5 million. In addition, BancorpRI announced its quarterly dividend of $0.19 per share, which will be paid on August 31, 2011 to shareholders of record on August 10, 2011.

17

Table of Contents

SELECTED HISTORICAL FINANCIAL DATA FOR
BROOKLINE AND BANCORPRI

Brookline Selected Historical Financial and Other Data

        The following tables set forth selected historical financial and other data of Brookline for the periods and as of the dates indicated. The historical consolidated financial data as of and for each of the years in the five-year period ended December 31, 2010 have been derived in part from Brookline's audited financial statements and related notes incorporated by reference into this proxy statement/prospectus. The information at and for the three months ended March 31, 2011 and 2010 is unaudited. However, in the opinion of management of Brookline, all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of the results of operations for the unaudited periods have been made. The selected operating data presented below for the three months ended March 31, 2011 are not necessarily indicative of a full year's operations.

18

Table of Contents