A Union Pacific Corp. (UNP) executive urged members of Congress Tuesday to oppose pending legislation that would strip longstanding antitrust exemptions for freight railroad companies, saying the bill would discourage private investment in the industry and harm the public.

Testifying on behalf of the railroad industry, J. Michael Hemmer, a senior vice president with Union Pacific, said the legislation would treat railroads differently from other regulated industries and subject them to a confusing regulatory regime.

The real purpose of the bill, Hemmer said, was to overturn decisions of the Surface Transportation Board - which regulates the rail industry - that shippers don't like.

"This bill goes considerably beyond repealing statutory [antitrust] immunities," he said.

Hemmer said the current regulatory regime has provided significant public benefits, and he predicted that the proposed changes would create uncertainty and make it harder for companies to raise private capital.

A version of the railroad legislation passed committees in both the House and Senate last year but progressed no further. The Senate Judiciary Committee passed the legislation again in March.

On Tuesday, some House subcommittee members in both parties expressed basic support for the bill.

Rep. Hank Johnson, D-Ga., the chair of the subcommittee, said the antitrust exemptions for railroads have contributed to higher shipping prices that translated into higher prices for consumers.

"As a matter of public policy, we shy away from antitrust exemptions," Johnson said.

Representatives of the American Bar Association and the Consumer Federation of America both testified in support of the legislation.

"Now is the time to give competition a chance and reform this industry," said Mark Cooper, director of research at the Consumer Federation.

In addition to stripping antitrust exemptions, the bill would provide that federal trial judges don't have to defer to the jurisdiction of the Surface Transportation Board.

The legislation also would give private litigants the ability to seek court injunctions to block conduct by the rail companies.

Four rail companies dominate the rail shipping business: Norfolk Southern Corp. (NSC), Burlington Northern Santa Fe Corp. (BNI), CSX Corp. (CSX) and Union Pacific.

-By Brent Kendall, Dow Jones Newswires; 202-862-9222; brent.kendall@dowjones.com