A pair of U.S. Marine Greco-Roman wrestlers claimed medals at the 2000 Haparanda Cup in Haparanda, Sweden, Dec. 2-3.    Both wrestlers competed at 187.25 pounds, with Kenny Owens (Quantico, Va./U.S. Marines) winning a silver medal and Jacob Clark (Quantico, Va./U.S. Marines) claiming the bronze medal.    Owens had a 3-1 record in the tournament, including a 3-0 victory over Clark in the semifinals. He was defeated by Alexandre Moldashev of Russia, 3-1, in the gold-medal finals.    Clark also went 3-1 in the competition, with his only loss to Owens. He scored an injury default over Matthias Erikson of Sweden in the bronze-medal match.    Placing fourth in the competition was Dan Hicks (Quantico, Va./U.S. Marines) at 213.75 pounds. Hicks won his pool competition with three straight victories, then lost his final two bouts. He was defeated 7-1 by Ruslan Kostenko of Ukraine in the bronze-medal match.    The U.S. Marines placed in a tie for fifth place with Finland in the tournament. Russia won the team title, followed by the St. Petersburg club of Russia, then Ukraine and Sweden. The Marines team was led by U.S. Marine Corps head coach Jay Antonelli of Quantico, Va.