The announcement follows weeks of intense congressional pressure on Martin, a Republican, to delay a planned Dec. 18 vote on altering the media ownership restrictions. The House and Senate Commerce committees are planning December hearings to further review the FCC's plans.

During a Tuesday conference call with reporters, Martin said the proposal involves "a relatively moderate change" that's warranted to strengthen struggling newspapers. The relaxation, if adopted, could enable the buyout of the Tribune Co. by real estate mogul Sam Zell, who has said he hopes to complete the transaction by year's end.

The deal requires waivers in five markets to close. Under the FCC proposal, combinations could potentially be allowed in Chicago, Los Angeles, Miami and New York but would be barred in the fifth market, Hartford, which is outside the top 20.

Lawmakers and watchdogs quickly blasted the announcement. "The FCC still has not completed a separate proceeding with a thorough study of the impact of media concentration on localism," said Sen. Byron Dorgan, D-N.D., referring to broadcaster commitments to local coverage.

In a statement, Dorgan said that item is a necessary "prerequisite to any discussion of whether media ownership rules ought to be changed." He has introduced legislation with colleagues from both parties that would force the agency to delay the vote.

In an interview, Ben Scott, director of the advocacy group Free Press, dubbed the plan "corporate welfare" for media conglomerates. He warned that the proposal could be interpreted as relaxing waiver requirements in markets outside the top 20.

"He's opened up a giant loophole for waiver applications" from the ban in smaller markets, Scott said. Martin emphasized during the conference call that small-market combos would be "presumed" prohibited unless proven otherwise.

"Despite his protestations that this move is good for newspapers, Martin is really just working to aide the Tribune company," wrote Jeff Chester, executive director of the Center for Digital Democracy, in a statement.

In an effort to soften the criticism, the FCC emphasized in its announcement that the recommendation is "more conservative" than a 2003 effort to ease the rule and that no other media limits under review would be altered.

The FCC has granted exemptions from the ban by grandfathering combinations that predate its 1975 adoption of the media rules and through waivers to aid struggling properties.

For a large-market combination involving a television station, there must be at least eight independently-owned and operated "major media voices" left after the transaction. In addition, the TV station cannot be among the market's top four. The FCC also would consider a market's level of concentration, the impact of a combination on local news and editorial independence, and the financial condition of a paper.