NEW YORK, Aug. 13 -- FiberNet Telecom Group Inc. has entered into exclusive agreements to build and operate a broadband fiber optic transmission network within the Chrysler Center, which is currently undergoing a major redevelopment by Tishman Speyer Properties, its owner and manager. FiberNet has the exclusive right to use up to eight strands (384 fiber miles) of Metromedia Fiber Network Inc.'s dark fiber network in the metropolitan New York area.