Curtis Davies has finally sealed his long-awaited move from West Bromwich Albion after joining Aston Villa on a season-long loan with a view to a permanent move next summer.

It is understood that should the transfer go through, the deal will be worth an initial £8.5 million, rising to £10m with add-ons. After months of speculation over his future, the England Under-21 centre back made his position at The Hawthorns untenable when he handed in a transfer request in July after West Brom failed to win promotion back to the Barclays Premier League.

Davies became the club’s most expensive defender when Bryan Robson, the former manager, signed him from Luton Town for £3 million in August 2005. Despite being unable to prevent his team from being relegated from the top flight that season, Davies made such an impression that he was made occasional captain of the side - an honour he was given full time for 2006-07.

He missed much of last season after twice breaking the same metatarsal bone in his left foot, and he is yet to play this season under Tony Mowbray, the manager.

“The supporters are well aware that Curtis wanted to leave the club and play in the Premiership,” Mowbray said. “I want to thank him for his efforts and total commitment to the cause last season. However, since our defeat at Wembley [in last season’s play-offs final], he clearly felt his future lay elsewhere. This has resulted in Curtis not wanting to play for the team this season.

“Although he’s a player of undoubted quality, we only want players here who are fully committed to the cause, which is what I’ve stressed all summer.

“Curtis hasn’t contributed during the first five games and, with there being plenty of competition for places in central defence, I think this deal suits all parties.”

Davies played for West Brom 73 times, scoring two goals. The deal with Villa is similar to that struck by West Brom and Manchester United for Tomasz Kuszczak, the goalkeeper. If the total fee for the transfer does reach £10 million it would surpass the club record of £9.5million, paid to River Plate for Juan Pablo Angel, the forward, in 2001.

Davies becomes Villa’s second centre back signing in 48 hours after Zat Knight joined from Fulham in a £3.5million deal on Wednesday and he could make his debut in Sunday’s home clash with Chelsea. He is Martin O’Neill’s fourth summer signing after Knight, Nigel Reo-Coker and Marlon Harewood.