ITALY'S AGIP PETROLI BUYS STAKE IN U.S. COMPANY State oil firm Agip Petroli Spa said it has acquired a 50 pct stake in Steuart Petroleum Co, an independent U.S. Oil products company. Financial terms were not disclosed. Agip Petroli, a subsidiary of state energy concern Ente Nazionali Idrocarburi, said in a statement that the remaining 50 pct of the U.S. Firm is owned by Steuart Investment Co, a holding company that also operates in the sectors of transportation, hotels and insurance. The Italian firm said Steuart Petroleum operates primarily on the East Coast.