The new tower, as sketched out by a proposal for the Hudson Yards development site by the Durst Organization and Vornado Realty Trust, would be exclusively for Conde Nast and would be built to 1.5 million square feet.

Mr. Durst told The Observer this afternoon that Conde Nast would consolidate its offices in the new tower and would move out of the roughly 700,000 square feet that it currently occupies at Mr. Durst’s 4 Times Square. The Conde Nast lease at 4 Times Square ends in 2018, but Mr. Durst said a deal would be negotiated to let them break the lease by 2015.

This is all under the condition that the Durst Organization and Vornado win the bid to develop the Hudson Yards site. Bids are due Oct. 11 to the Metropolitan Transportation Authority, the yards' owner, and other companies preparing proposals include The Related Companies, Brookfield Properties and Tishman Speyer.

The news that Conde Nast wants to build a new tower was reported by Women's Wear Daily this morning. (The New York Times also reported this morning that Morgan Stanley has teamed with Tishman Speyer on a proposal to build a new headquarters on the yards.)

Mr. Durst told The Observer that having Conde Nast already secured as an anchor tenant for one of its towers can only help the position of its bid with Vornado.

“We think it’s a tremendous advantage,” he said. “We are very excited about it. We hope it’ll help our bid. We think the team we put together has put us in an excellent position.”

A call to a Conde Nast spokeswoman was not immediately returned.