Media groups may own up to 12 television stations provided each owner reaches no more than 25 percent of the national audience, the Federal Communications Commission decided yesterday, adopting a compromise worked out with congressional leaders.

The new limit on audience reach modifies a move by the FCC in July to increase the number of television stations and AM and FM radio stations that one owner can hold to 12 of each from seven.

The FCC drew fierce opposition in July when it replaced the "7-7-7" rule with the "12-12-12" rule, with no limit on audience reach, and announced plans to eliminate the restrictions entirely in six years.

Members of Congress joined the Motion Picture Association of America in opposing the total phase-out of restrictions, arguing that it would allow the major networks to buy more independent stations and increase their domination of the industry.

The FCC and Congress worked out the compromise rule hoping to increase competition with the three dominant networks for television programming.

The big three -- ABC, CBS and NBC -- each currently own stations that reach about 20 percent of the viewing audience and, as a practical matter, would only be able to buy two and possibly three more stations under the plan.

Groups such as Storer Communications, Westinghouse Broadcasting, Gannett Corp. and the Washington Post Co. would be able to buy as many as seven or eight new stations.

Rep. Timothy E. Wirth (D-Colo.), chairman of the House subcommittee on telecommunications, praised the FCC decision, saying it would permit expansion of the independent broadcast groups while "serving as an effective check against excess concentrations" in the industry.

Wirth noted that the new rules "mirror all the key provisions" of legislation that he introduced earlier this year along with Reps. Mickey Leland (D-Tex.) and John D. Dingell (D-Mich.).

Audience reach under the new rule will be determined by Arbitron market rankings of the percentage of national TV households contained in a market. Because of the limits of the UHF signal, UHF television stations will be charged for only 50 percent of the households in a market.

The new rule sparked dissent by one commissioner over a provision designed to encourage minority ownership of broadcast stations. The provision, modeled on one designed by Rep. Leland, allows media groups to own up to 14 television stations reaching no more than 30 percent of the national audience if two of the stations are controlled by members of minorities. The additional 5 percent audience share must also come from stations that are "more than half" owned by minorities.

Commissioner Dennis R. Patrick said he dissented "to that part of the decision that sets two different national ownership rules based on race." The ownership rule should ensure "that no single individual controls access to too large a segment of the American public. Surely, this is not an issue that turns on race," Patrick said.

The new rule takes effect April 2.

The FCC, in other action, decided to allow the Communications Satellite Corp. (Comsat) to sell its services directly to users rather than through other communications companies.

Comsat had been restricted since 1966 to the role of a "carrier's carrier," leasing satellite circuits to communications carriers such as American Telephone & Telegraph Co., which in turn leased the circuits to large business customers.

Comsat, through a separate corporate subsidiary, can now lease circuits directly to the business customers.

The FCC said that freeing Comsat to compete may lead to lower rates for leased-channel services.