A MAJOR offshore pipeline project across four west African countries has received the go-ahead, a source associated with the project said on Tuesday. The cost of the project, which is expected to carry natural gas from Nigeria to Benin, Togo and Ghana, is estimated at $430 million. The 1,030km pipeline will be financed by a consortium comprising the Ghana National Petroleum Corp., Chevron, Shell, Nigeria Gas Co., Sotegaz of Togo and Sobegaz of Benin. The pipeline is expected to be completed by July 2002.