Town manager Joe Royle has handed striker Alun Armstrong a free transfer. The former Stockport and Middlesbrough player has had a season hit by injuries, only recently returning to action after breaking his wrist.
Royle told the club site: "We are quite well off in some areas of the squad and I think Alun has looked a little stale at times this season.
"He needs a new challenge to bring the best out of him and we wish him well.
"He's a lovely lad with lots of talent and we wish him every success in finding a new club and enjoying a good future in the game."
Armstrong joined Town for a fee of £500,000 from Middlesbrough in December 2000. He has since scored 17 goals in 85 appearances.