Sun Co., a leading producer and distributor...

Sun Co., a leading producer and distributor of gasoline and petroleum products, said it has agreed to buy the smaller Atlantic Petroleum Corp. for $513 million. The acquisition is to be made, Sun Chairman Robert McClements Jr. said, by purchasing all shares of Atlantic Petroleum Maatschappij BV, a Netherlands holding company. The holding company is owned by John Duess, who bought the Atlantic properties from Atlantic Richfield Co. in 1985 for $420 million.