Striker Clayton Donaldson has turned down an offer of a new contract at Brentford and has signed for Birmingham City.

The forward, 30, will join Birmingham – who escaped relegation to Sky Bet League One with a goal seconds from the end of the 2013/14 season – when his contract expires on Monday, June 30.

Clayton has been with Brentford since the summer of 2011, when he signed from Crewe Alexandra.

In three seasons at Griffin Park the striker played 155 games in all competitions and scored 53 goals.

In 136 League One games – he missed just two in three years in TW8 – Clayton scored 46 goals.

Mark Warburton, Brentford FC Manager, said: “Clayton was an important member of the squad last year.

“We were delighted with his contribution.

“As a result, we sat down with him and offered a very good two-year contract with an option for a third year.

“The contract met all the demands of the player and the agent and every indication was given that the offer was more than acceptable.

“However, the way in which the game now appears to work means that clubs receive mixed messages and as a result Clayton has joined another Club.

“From our perspective, we only want players that are 100 per cent committed to Brentford Football Club.

“We wish Clayton well but any replacement will play an important part in an exciting time ahead.”