A House subcommittee unanimously approved a bill yesterday that would give the patent rights for inventions financed with federal funds to the businesses and universities that produce them, rather than keep the rights in the public domain.

The controversial proposal has stirred little opposition in an election year when flagging U.S. productivity is a target for Democratic and Republican alike.

In April the Senate approved, 94 to 4, a similar bill, although it would limit the issuing the patent rights to small businesses, nonprofit organizations and universities.

Sen. Birch Bayh (D-Ind.), sponsor of the Senate bill, believes that inclusion of big business in the House version spells the measure's defeat.

Main opposition to the concept has come from Sen. Russell B. Long (D-La.), who calls it "one of the most radical and far-reaching giveaways" he has ever seen.

The defense industry opposes the House version of the bill. The Defense Department currently gives contractors exclusive title to all inventions financed with federal funds; the House bill would require contractors to apply for patent rights in specified fields.

The federal government now pays for well over half the research and development in the United States -- an investment of about $30 billion annually, of which 65 percent is for military research and development. Small business gets 3.4 percent of the federal outlay.

The bill, part of President Carter's program to foster industrial innovation, is intended to encourage commercialization of new ideas by giving businesses and universities 17-year monopoly rights to their inventions.

The bill's proponents in the House, led by Robert W. Kastenmeier (D-Wis.), believe that exclusive rights are a necessary incentive to commercialization.

Long argues that the inventions are more likely to be used if they are available to anyone, and that consumers would wind up paying more if the inventions are allowed to be monopolized.