The Arizona Diamondbacks announced Friday that the club has signed first baseman Tony Clark to a two-year contract extension. Financial terms were not disclosed. Clark, who signed a one-year deal with Arizona while a free agent during the offseason, is enjoying one the finest campaigns of his 11-year career in 2005. The switch-hitting slugger is hitting a career-best .329 with 18 home runs and 55 RBI in 83 games, and is 13-for-35 (.371) with three homers and 15 RBI as a pinch-hitter. "Getting Tony under contract to remain a Diamondback has been on the front burner for several weeks," said team general partner Jeff Moorad. "He has not only been instrumental in the club's success on the field, but his personality and leadership skills have been a tremendous asset in our clubhouse." Clark, a resident of nearby Glendale, is a career .268 hitter with 209 homers and 690 RBI. The 33-year-old was the second overall pick of the 1990 draft by Detroit and played for the Tigers, Red Sox, Mets and Yankees before signing with Arizona.