PRAGUE, Czechoslovakia (AP) _ Hannu Jarvenpaa scored his eighth and ninth goals of the World Hockey Championships Thursday night as Finland trounced Sweden 6-1 in the final regulation round game.

Earlier, West Germany defeated East Germany 4-1. The East Germans finished last in the eight-team championship and will be relegated to the B group next year. Poland, winner of the B group championships earlier this season, will replace East Germany in the A group next year.

Finland finished fifth in the championships with Sweden sixth and West Germany seventh.

Canada and Czechoslovakia play the gold medal game here Friday while the United States faces the Soviet Union in the bronze medal game.

Uli Hiemer, who played for the New Jersey Devils in the National Hockey League this season, Michael Betz, Harold Kreis and Franz Reindl scored for the West Germans.