The head of the Federal Communications Commission has circulated an ambitious plan to relax the decades-old media ownership rules, including repealing a rule that forbids a company to own both a newspaper and a television or radio station in the same city.

Kevin J. Martin, chairman of the commission, wants to repeal the rule in the next two months - a plan that, if successful, would be a big victory for some executives of media conglomerates.

Among them are Samuel Zell, the Chicago investor who is seeking to complete a buyout of the Tribune Company, and Rupert Murdoch, who has lobbied against the rule for years so that he can continue controlling both The New York Post and a Fox television station in New York.

If we don't act to improve the health of the newspaper industry, we will see newspapers wither and die. Without newspapers, we would be less informed about our communities and have fewer outlets for the expression of independent thinking and a diversity of viewpoints. The challenge is to restore the viability of newspapers while preserving the core values of a diversity of voices and a commitment to localism in the media marketplace.

Eighteen months ago, the Federal Communications Commission began a review, ordered by Congress and the courts, of its media ownership rules. After six public hearings, 10 economic studies and hundreds of thousands of comments, the commission should move forward. The commission should modify only one of the four rules under review - the one that bars ownership of both a newspaper and a broadcast TV or radio station in a single market. And the rule should be modified only for the largest markets.

His plan was criticized by some lawmakers, who said it would lead to too much consolidation. They have introduced legislation to delay action by the commission.

''The chairman of the Federal Communications Commission has put forward what I'm sure he regards as a reasonable compromise on the issue of media consolidation,'' said Senator Byron Dorgan, Democrat of North Dakota. ''But he has yet to make the case for why any further media consolidation is necessary. Indeed, he is relying on an assumption that newspapers are doomed and that cross-ownership is necessary to save them. I believe this is not the case.''

The plan was also attacked by the Newspaper Association of America, which complained that it was too modest and that Mr. Martin did not go far enough.

''The fundamental issues he raises concerning the vitality of newspapers and assuring that local news remains available to the public in print and in broadcast are not confined to the top 20 markets,'' said John F. Sturm, president and chief executive of the trade organization.

It was also challenged in a statement by the two Democrats on the commission, Michael J. Copps and Jonathan S. Adelstein.

Martin has said that it is time to complete the process, which will have incluced one-dozen public hearings stretching back several years once the FCC holds its final media-ownership hearing in Seattle Friday. He plans to release for public inspection his proposed rule changes Nov. 13, according to sources, with four weeks for public comment and a vote Dec. 18.