SUNTER BEGINS TENDER FOR ALLEGHENY <AG> Allegheny International Inc said Sunter Acquisititon Corp, formed by First Boston Inc, began a cash tender offer in accordance with their previously announced merger agreement for all the outsanding shares of Allegheny's common stock, 2.19 dlr cumulative preference stock and 11.25 dlrs convertible preferred stock. The offer expires April 9, unless extended. Under terms of the agreement, tendering shareholders will receive 24.60 dlrs per common share, 20 dlrs per preference share and 87.50 dlrs per preferred share. Allegheny said the offer is conditioned upon the valid tender of stock representing a majority of the voting power and at least two-thirds of outstanding shares of preference stock and preferred stock. The merger agreement was announced earlier this week.