A Maryland hotel executive is trying to assemble new financing for a $680 million offer to buy Tribune Publishing after his partner, a Swiss billionaire, pulled out of the bidding for the newspaper chain.

Stewart Bainum is talking to other potential investors after Hansjorg Wyss dropped out in the last few days, a person familiar with the matter said Sunday.

Wyss told Bainum that it would require too much investment to turn the chain’s flagship Chicago Tribune into a nationwide publication, according to the person, who spoke anonymously because they were not authorized to discuss the private negotiations.

Wyss and Bainum offered to buy the chain for $18.50 per share, topping a previous offer of $17.25 per share, or $634 million, by Tribune’s largest shareholder, hedge fund Alden Global Capital. Bainum told Tribune representatives about Wyss’ withdrawal on Friday, and they authorized him to talk to other potential investors, according to the person familiar with the matter.