Abbott Laboratories' (ABT) $6.6 billion purchase of Solvay SA's (SVYSY) drug business continues a busy stretch of acquisitions for Abbott and bolsters the company's reputation of looking outside the company for growth.

Under the decade-long tenure of Chairman and Chief Executive Miles D. White, some of Abbott's biggest products - including its top seller, the drug Humira - were purchased rather than developed in-house from scratch. The Solvay deal, which comes as Abbott fends off concerns over slowing Humira growth, is one of several Abbott has made recently to diversify the business and add potentially promising products.

White indicated Monday that the company won't stop here. The cash-backed Solvay deal doesn't leave Abbott financially or strategically constrained, he said.

"We continue to be in the hunt for a number of smaller assets," White said.

Abbott shares rose 3.2% Monday to $48.86 amid a surge for the broader market and on forecasts that the Solvay deal, expected to close in the first quarter next year, will immediately add to Abbott's earnings.

The Solvay news follows Abbott's Sept. 10 announcement that it plans to spend up to $410 million to buy privately held Evalve, which makes a system to repair damaged heart valves without major surgery. It's a tiny business and only outside the U.S. thus far, but Abbott believes the market could eventually be worth several billion dollars.

Other recent deals include the purchase of Indian nutrition business Wockhardt Ltd. (532300.BY) and a $400 million deal to buy Visiogen Inc., which makes replacement lenses for cataract patients. Those followed the $1.36 billion acquisition of vision-care company Advanced Medical Optics in February.

These moves represent a mix of quick boosts to sales and earnings, and fliers on small but potentially lucrative products. Matthew Loucks, a portfolio manager with Abbott shareholder Sit Investment Associates in Minneapolis, isn't a fan of the bigger Solvay and Advanced Medical purchases, but he likes smaller transactions that beef up Abbott's pipeline.

That is particularly important for the company, which Loucks said hasn't "been overly successful in developing their own products."

But Abbott has had success when it comes to acquiring and then further developing key products. The top example is Humira, a drug used for various types of arthritis and inflammatory diseases that came from the $6.9 billion Knoll Pharmaceuticals purchase in 2001. Humira, which has continued to gain access to new markets under Abbott, posted $2.33 billion in 2009 sales through June.

Abbott's purchase of Guidant Corp.'s vascular business in 2006, for $4.1 billion plus various payments and a loan to Boston Scientific Corp. (BSX), proved to be another winner. It gave Abbott the "Xience" stent - a scaffold for clogged heart arteries - which later became a market-leading device behind strong clinical study data.

To Loucks' point, Xience arrived just in time to offset a home-grown Abbott stent program canceled due to less-impressive data.

The Humira and Xience home runs put pressure on Abbott to keep the good times rolling, now that both products are maturing and losing prior high-growth steam. Abbott's White, for his part, said the Solvay deal should reinforce the company's growth prospects.

Abbott spent about 9% of sales on R&D in the first half of 2009, which matches the company's projection for the full year. By comparison, Johnson & Johnson (JNJ) - the huge pharmaceutical and medical-products conglomerate with which Abbott is often compared - spent 10.4% of first-half sales on R&D.

Buying Solvay's drug business will add about $500 million to Abbott's annual R&D investment, and will lift spending as a percentage of sales by at least half a point, Abbott said.

White said Abbott has a "very, very healthy" early and mid-stage pipeline of products it discovered that isn't well-known. Adding Solvay's drug business bolsters Abbott's ability to fund and move its own pipeline forward, White said.

-By Jon Kamp, Dow Jones Newswires; 617-654-6728; jon.kamp@dowjones.com