Terry Holt, a spokesman for Mr. Zell, referred all questions about the deal to Gary Weitman, a spokesman at Tribune. Mr. Weitman declined to comment. In an e-mail message to employees, the chief executive, Dennis J. FitzSimons, said Tribune still hoped to close the transaction by the end of the year. He also said that the company would “seek an expansion of cross-ownership relief” beyond what was contained in Mr. Martin’s plan.

Commission officials said that Tribune representatives had been in discussions with officials to try to come up with a way for the commission to provide enough of a signal of its intentions to satisfy the bankers.

But for media deals in the future, it is unclear whether the new rules will make it significantly easier for conglomerates to own both a newspaper and a station in most markets.

In telephone briefings with reporters, Mr. Martin said the commission would consider granting exemptions if other combinations were in the public interest, but that the “presumption would be against them.”

The proposal would require the commission in granting exemptions to consider the level of media concentration and make a finding that the companies involved would increase the amount of local news. It would require a commitment that both the newspaper and the station exercise independent news judgment. Finally, the commission would be obliged to consider the financial condition of the newspaper, and whether the owner was committed to invest significantly in the operations of a paper in distress.

In announcing his plan, Mr. Martin said he sought to strike a compromise that would assist what he said was a financially ailing newspaper industry while trying to be sensitive to concerns about the effects of media consolidation on the quality of news coverage.

“The newspaper industry has faced significant challenges recently and I feel we have to do all we can to ensure we continue to have a vibrant industry,” Mr. Martin said.