Union Minière SA of Brussels, Belgium, and II-VI Inc. of Saxonburg, Pa., returned to the bargaining table with San Diego-based infrared optics manufacturer Laser Power Corp., following Laser Power's adoption of a takeover defense late last year. Each company has extended a merger agreement under which it would make Laser Power a wholly owned subsidiary.

Union Minière would purchase all outstanding shares for $4 each in a transaction worth more than $38 million. II-VI has countered with an offer of cash and stock of $2.32 and 0.052 shares of II-VI per share of Laser Power, at a guaranteed minimum value of $4.05 per share.