ANTWERP, Belgium (March 4)—Bayer A.G. and Shell Petroleum N.V. will close their Bayer-Shell Isocyanates N.V. joint venture by June 30, formalizing a decision previously signaled by the two partners. The 270-employee toluene diisocyanate and diphenyl methane diisocyanate production operation will be shut because of its relatively small scale, the firms said. With annual capacities of 30,000 and 36,000 metric tons for TDI and MDI, respectively, BSI was considered economically unviable in an increasingly competitive urethanes market. Bayer markets all the MDI produced at the Belgian unit, while Shell markets all the TDI production. Following the closure, Bayer said it will supply customers from its international production network. Shell, which has no other TDI production activities, said it will supply the raw material via global procurement agreements.