After months of speculation, his mercurial hedge fund, SAC Capital, is near a deal to take 66,000 square feet, or the second through fifth floors, multiple sources said. Rumors of the deal have been swirling for months, but a lawsuit by Mr. Cohen's ex-wife, which included allegations of insider trading, are said to have held up the signing. A judge threw out the case yesterday, and sources said the deal could now be signed in a matter of days.  

The huge lease—which earlier media reports said could include coveted naming rights to the building—would be a turning point for the glimmering Club Med of office towers, built and lost by Harry Macklowe to Mort Zuckerman's Boston Properties in September 2010 for $275 million. The building, with a pool and health club, has a sole tenant: Senator Investment Group, which took the 28th floor for a rent above $100 a foot in November. 

SAC Capital is currently spread over multiple floors at nearby 540 Madison and is headquartered in Stamford, Conn.

More details to follow. For now, Boston Properties declined to comment and CB Richard Ellis' Paul Amrich, the broker for 510 Madison, did not return calls for comment. SAC Capital's broker, Newmark Knight Frank's Neil Goldmacher did not respond to requests for comment. 

lkusisto@observer.com