STURBRIDGE, Mass., July 8 -- SpecTran Corp. has sold its interest in General Photonics LLC, its joint venture with General Cable Corp., to BICC General Cable Industries, Inc. for $2,367,200. SpecTran and General Cable formed General Photonics, a manufacturer of optical fiber cables, in 1996.As part of the transaction, General Photonics repaid to SpecTran a loan of $325,000, and BICC General Cable purchased approximately 30,000 kilometers of optical fiber from SpecTran's Communication Fiber Technologies subsidiary.