Walter Berry, 6-foot-8 junior who averaged 23 points and 11 rebounds a game for a St. John's team that exceeded all expectations, has been named college basketball player of the year by United Press International.

In a nationwide vote of 125 writers and broadcasters, Berry won by about a 2 1/2-to-1 margin over his closest competitor, Johnny Dawkins of Duke, 43-17. Len Bias of Maryland was third with 11 votes . . .

Georgia Tech assistant George Felton is the new basketball coach at South Carolina, his alma mater (class of '75). Replacing Bill Foster, who resigned after a losing season, Felton said his top priority will be to return the Gamecocks to national prominence. He starts on a four-year contract worth $65,000 a year . . .

Navy Coach Paul Evans is scheduled for another round of interviews today with University of Pittsburgh officials now that his Midshipmen have been eliminated from the NCAA tournament . . .

Northwestern's football coach, Dennis Green, an apprentice under Coach Bill Walsh at Stanford and again with the San Francisco 49ers, resigned his duties in Evanston, Ill., to join Walsh's 49ers staff. Despite returning a measure of respectability to Northwestern, Green never produced a winning team in his five-year tenure -- 10-45 overall, 7-37 in the Big Ten.

Doug Single, Northwestern athletic director, said a replacement could be named as early as Wednesday.