The Athletics have reached agreement on a three-year contract to keep Bob Melvin as their permanent manager. Melvin, 49, took over in an interim capacity for the fired Bob Geren in June and has a 42-49 record after Tuesday night's 7-2 loss to the AL West-leading Rangers at the Coliseum. Geren's dismissal marked the first time Oakland fired a manager during the season in a quarter-century.