A House subcommittee approved legislation yesterday to scale back exemptions from federal antitrust laws that the insurance industry has enjoyed for 45 years.

On a 9 to 6 partisan vote, the Judiciary Committee's subcommittee on economic and commercial law approved a bill to subject insurance companies to federal lawsuits for price fixing and other antitrust provisions. All Democrats on the panel voted for the bill and all Republicans voted against it.

Insurance companies and their agents have enjoyed immunity from antitrust suits under the 1945 McCarran-Ferguson Act, which delegated regulation of the now-$500 billion industry to state governments.

The bill clearing its first legislative hurdle yesterday was prompted by the 1985 insurance upheaval in which companies quit writing liability coverage for various occupations because of huge claims and judgments against them.

A similar bill was approved by the subcommittee in 1988, but got nowhere because of intense opposition from the insurance industry. This time, however, Rep. Jack Brooks (D-Tex.), the full committee's new chairman, is determined to bring a bill to the House floor.

Citing opponents' claims that the industry is so competitive that no antitrust laws are needed, Brooks said yesterday, ''If that's so, then there is nothing to fear'' from the bill.

In addition to price fixing, the legislation would, after a five-year transition, make other alleged abuses by insurance companies grounds for federal antitrust lawsuits. They include dividing up geographic territories among competing companies and ''tying'' requirements, such as forcing a buyer to purchase home insurance in order to get auto coverage.

Sen. Howard Metzenbaum (D-Ohio) has introduced similar legislation in the Senate. However, the industry is counting on opposition from Sens. Dennis DeConcini (D-Ariz.) and Howell Heflin (D-Ala.) -- both, along with Metzenbaum, members of the Senate's Judiciary Committee -- to prevent its passage.