Jeff Wachtel has exited his post as prexy of Alliance Atlantis TV Production as part of the post-merger executive shakeout at the Canadian film and TV concern.

Wachtel’s responsibilities had overlapped the duties of Peter Sussman, prexy of Alliance Atlantis Entertainment and one of the company’s four controlling partners.

Wachtel, a former top exec at Columbia Pictures TV, joined Alliance TV last July, just weeks before Alliance inked its merger agreement with fellow Canuck production-distribution outfit Atlantis Films.

During his short tenure, Wachtel supervised Alliance Atlantis’ syndie and network TV development, including the upcoming syndie actioner “Beastmaster: The Legend Continues.” He’ll continue to supervise the production of “Beastmaster’s” first 22 segs, which begin lensing next month in Australia.

In his six years at Col, Wachtel helped develop the much-praised Fox drama “Party of Five” and the WB Network’s teen hit “Dawson’s Creek.” In between gigs at Col and Alliance, he also headed the 3 Arts Entertainment joint venture of Col, CBS and 3 Arts Management, a production partnership that yielded the syndie drama “Pensacola: Wings of Gold.”