Aston Villa have confirmed that striker Darren Bent has been released by the club.
The 31-year-old joined the Villans from Sunderland in January 2011 for a club-record fee of £24m.
Bent, who scored a total of 25 goals in 72 games for Villa, was loaned out to Fulham and Derby County in recent seasons after struggling for first-team action.
The former England international is expected to sign a permanent deal with Derby before the start of the 2015-16 campaign.
Defender Enda Stevens has also been released by Villa following the end of his contract.
