ALLEGHENY <AI> SUED OVER PROPOSED BUYOUT Allegheny International Inc said it and First Boston Inc's <FBC> Sunter Holdings Corp subsidiary have been named as defendants in a class action filed in the Court of Common Pleas for Allegheny County, Pa., which seeks an injunction against Allegheny's proposed merger into Sunter. The company said its board and some former directors and First Boston were also named as defendants. It said it and Sunter intend to vigorously oppose the action. Allegheny said the class action suit alleges the price to be paid in the transaction is grossly unfair. The company said the suit's allegations are similar to those contained in an earlier federal court suit.