Vector Graphic and Dual Systems delayed merging.

Westlake Village-based Vector Graphic, a microcomputer manufacturer, and Dual Systems Control of Berkeley, which makes multiuser computer systems, extended indefinitely an agreement in principle for Dual to merge into Vector. The companies also extended the contract under which Dual Systems manages Vector Graphic. Bernardus Smit, president of Dual Systems, declined to elaborate on the reasons for the delay, and Vector Graphic officials were unavailable for comment.