Sumitomo Metal Industries Ltd. and Mitsubishi Materials Corp. announced Tuesday they will fully integrate their silicon wafer operations by forming a new joint venture in January.

The two firms are already cooperating in the development and production of next-generation wafers through Silicon United Manufacturing Corp., a 50-50 joint company they set up in July 1999.

Under the latest deal, the two firms will transfer all their silicon wafer-related operations, including Sumco, into the new venture, a Sumitomo Metal spokesman said.