AT&T?s Submarine Systems International (ssi) subsidiary, Morristown, NJ, has signed a $17.6 million contract with state-owned Brazilian oil firm Petroleo Brasileiro SA to provide what the company calls the first undersea fiber-optic cable network exclusively designed for offshore oil platforms. The 475-mi network will connect Petroleo Brasileiro?s fixed and floating platforms in the Campos Basin region of the South Atlantic to a shore base north of Rio de Janeiro. The network will use ssi?s SL100 fiber-optic cable technology for multimedia transmission at rates ranging from 155 to 622 Mbits/sec, with available upgrades to 2.5 Gbits/sec. The network should be in service by June 1998. AT&T recently announced it is selling ssi to Tyco International Ltd.