FLATIRON MOVING IN WITH J.P. MORGAN

Silicon Alley venture fund Flatiron Partners is retreating from Silicon Alley and giving up its offices.

The fund, which in five years bankrolled at least 57 dot-com gambles, confirmed yesterday that it’s moving out to save “millions of dollars a year” in rent on its offices in the landmarked Flatiron Building.

The Post first reported that Flatiron partners Jerry Colonna and Fred Wilson – facing meager returns on their $500 million war chest – might be forced to take refuge in the uptown offices of its main backer, J.P. Morgan Chase & Co. Returns have fallen to 279 percent from 400 percent a year ago, Flatiron said.