A deal that would reshape the American newspaper industry has run into complications just one month after an agreement was reached, according to three people with knowledge of the matter. As a result, the New York hedge fund Alden Global Capital may have to fend off a new suitor for Tribune Publishing, the chain that owns major metropolitan dailies across the country, including The Chicago Tribune, The Daily News and The Baltimore Sun, the people said.

On Feb. 16, Alden, the largest shareholder in Tribune Publishing, with a 32 percent stake, reached an agreement to buy the rest of the chain in a deal that valued the company at $630 million. In the deal, Alden would take ownership of all the Tribune Publishing papers — and then spin off The Sun and two smaller Maryland papers at a price of $65 million to a nonprofit organization controlled by the Maryland hotel magnate Stewart W. Bainum Jr.

In recent days, Mr. Bainum and Alden have found themselves at loggerheads over details of the operating agreements that would be in effect as the Maryland papers transitioned from one owner to another, the people said. In response, Mr. Bainum has taken a preliminary step toward making a bid for all of Tribune Publishing, the people said.

Mr. Bainum has asked the Tribune Publishing special committee, a group made up of three independent board members, for permission to be released from a nondisclosure agreement prohibiting him from discussing the deal, so that he would be able to pursue partners for a new bid, the people said.