CHATTANOOGA, Tenn. (AP) — David Blackburn has stepped down as Chattanooga's athletic director, effective immediately.

Chattanooga announced Tuesday that Blackburn was leaving after four years to pursue other interests. Scott Altizer was selected interim athletic director while it seeks Blackburn's permanent replacement.

The Mocs won 13 Southern Conference regular-season titles and 10 conference tournaments under Blackburn.

Chancellor Steve Angle says "the Mocs have reached unprecedented heights over the last four years under David's leadership and we thank him for his efforts."

In the last year, Blackburn hired new football and men's basketball coaches. Tom Arth took over football after Russ Huesman left for Richmond. Lamont Paris was named basketball coach after UMass hired Matt McCall.

Blackburn said in a university release that "the time has come" for him to resign.