CALIFORNIA FIRM HAS FIVE PCT OF MODULAIRE <MODX> PBS Building Systems of America Inc, an Anaheim, Calif., company, told the Securities and Exchange Commission it has acquired 150,000 shares of Modulaire Industries, or 5.0 pct of the total outstanding common stock. PBS, whose subsidiaries design, make, sell and lease nonresidential relocatable modular buildings, said it bought the stake for 855,768.75 dlrs "to acquire an equity interest in Modulaire, while it evaluates Modulaire." Depending on several factors, PBS said it may decide to buy additional Modulaire common shares.