NORTHVILLE, Mich., Jan. 10 -- OIS Optical Imaging Systems Inc. announced that it has completed the sale of its assets to Guardian Industries Corp., as per the December 1999 agreement between the two companies. OIS received approximately $40.2 million in the deal, of which approximately $30.5 million was used to discharge all outstanding bank debt. The bank debt had been secured by OIS's assets, and the company's banks were unwilling to extend the terms of the loans beyond December 31, 1999. Through its majority-owned subsidiary, GD Investments Corp., Guardian Industries holds approximately 79.6 percent of the outstanding shares of OIS common stock, and all 91,137 outstanding shares of its Series B cumulative preferred stock.