Ed Cowan has called time on his six-season stint with Tasmania and will move back to Sydney to focus on his family, leaving his first-class future uncertain.

"I told Dan Marsh and my teammates on Sunday that I won't be playing cricket for Tasmania next year and it's with a very, very heavy heart that I told them," Cowan said. "It's time to be a family man who plays cricket rather than a cricketer with a family.

"And that's a very hard decision to make when cricket has been your number one priority for 15 years. But times change I guess and it's for a purely personal reason that we're going to be moving back to Sydney. I'm very sad but I'm confident it's the right thing to do."

Last winter Cowan signed a one-year deal with the Tigers on the condition he and his family were allowed to relocate partly to Sydney for personal reasons. He had also been in talks with New South Wales about returning as a contracted player with his home state, but chose ultimately to stay with Tasmania after they accepted his unusual terms. A further extension had been signed this season, but it was in the days after putting p[en to paper that Cowan had second thoughts.

"I made a mistake in signing it, but I didn't realise it was a mistake until I did," he said. "It was that point in time that I re-evaluated my priorities in life and it was literally the next day that I thought "this is me, again, prioritising cricket over my family' and that didn't sit comfortably.

"I've had a bit of a tough three weeks with very little sleep. It's affected my cricket which is disappointing because I really wanted to finish strongly, and I worked through ways that I could make next year work - I really wanted it to work for the team, to work for myself, to work for my family.

"But at the end of the day it was going to compromise my teammates because I would be backwards and forwards because my family was going to live in Sydney. It was going to compromise my team and compromise my own cricket preparation which isn't fair but most importantly it was going to compromise my family."

Cowan is the third-highest run-getter this Shield season, with 815 from nine games at an average of 47.94 and four centuries. He has spoken of a reinvigorated game and demonstrated a more aggressive style of play than had become his custom, but the pressures of spreading cricket and home life across two states have led him to leave the place where he was able to make the most of his ability.

Cowan debuted for his home state New South Wales in January 2005 but could not hold down a regular spot. It was the move to Tasmania in 2009-10 that brought him success and eventually an international run that lasted 18 Tests. Cowan represented Tasmania in 53 first-class matches and scored 4085 runs at 44.40, with 13 centuries.

George Bailey, the Tasmania captain, said while it was disappointing to lose Cowan, he could not begrudge him making the decision for family reasons.

"It is sad, but I think it's also a cause for celebration," Bailey said. "Ed had some wonderful years with us. I think he helped take our programme to another level. We achieved some great success. Really proud of the fact that he was able to achieve his personal dream of playing for Australia while playing for the Tigers. We certainly got the best out of him.

"We knew he was weighing those things up. I know he was really emotional when he spoke to the guys about the decision. We certainly know how much it mean to him and how hard a decision it was, so you can never begrudge someone who's making the decisions for those reasons."