The Justice Department's top antitrust enforcer on Wednesday questioned the need for a long-standing federal antitrust exemption for health insurance and medical malpractice insurance companies, but she stopped short of endorsing legislation to end the exemption.

"The Department of Justice generally supports the idea of repealing antitrust exemptions," Assistant Attorney General Christine Varney said in testimony to the Senate Judiciary Committee. "However, we take no position as to how and when Congress should address this issue."

Lawmakers in the House and Senate have introduced identical bills to strip the antitrust exemption for insurance companies, which was enacted in the McCarran-Ferguson Act of 1945.

The legislation would strip the exemption for egregious violations, such as price fixing, bid rigging and market allocation.

The bill's text indicates that it wouldn't affect the ability of states to regulate the insurance business.

Varney said repealing the exemption "would allow competition to have a greater role in reforming health and medical malpractice insurance markets than would otherwise be the case."

"There are strong indications that possible justifications for the broad insurance antitrust exemption in the McCarran-Ferguson Act when it was enacted in 1945 are no longer valid today," she said.

Sen. Charles Schumer, D-N.Y., called on his colleagues to add the antitrust legislation as an amendment to the health-care bill that Sen. Majority Leader Harry Reid, D-Nev., plans to bring to the floor later this month.

Reid made an appearance at Wednesday's hearing and offered strong support for stripping the antitrust exemption.

"Let's get this out of committee as quickly as possible and let's pass it," Reid said.

While Wednesday's committee hearing was well attended by Democrats, the only Republican to make an appearance was Sen. Orrin Hatch, R-Utah, who said he saw little evidence to justify a complete repeal of the antitrust exemption for insurance companies.

Lawrence Powell, representing the Physician Insurers Association of America, told lawmakers that eliminating the exemption would make it harder to price insurance. Powell also said that price fixing and other anticompetitive actions are already prohibited in insurance markets by existing state and federal laws.

The hearing comes the same week as America's Health Insurance Plans, or AHIP, circulated a controversial study projecting that the average family premium for health insurance would rise to $25,900 from $12,300 within 10 years if provisions included in Senate Finance Committee health-care legislation are enacted.

The study received a heated response from the White House and congressional Democrats, who accused AHIP of intentionally providing misleading information and not taking into account tax credits in the bill for low- and middle-income people to buy insurance.

Schumer on Wednesday called the insurance-industry study a blunder and said it may give lawmakers a "greater opportunity" to pass the antitrust bill.

Leading insurers in AHIP include Aetna Inc. (AET), Humana Inc. (HUM), Cigna Corp. (CI) and UnitedHealth Group Inc. (UNH).

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

(Patrick Yoest contributed to this article.)