Ambrose has had to battle with Matt Prior for a Sussex place

The player, who has recently struggled to command a first-team place, has agreed a three-year contract.

Ambrose said: "It was a tough decision but it's one that gives me a tremendous opportunity to further develop my game with one of the best clubs."

Mark Greatbatch, Warwickshire's new director of coaching, added: "Tim is a very good quality player."

Ambrose, part of Sussex's Championship winning side in 2003, has scored more than 2,000 runs at an average of 32.70 in 47 first-class matches.

But the success of Matt Prior, England's back-up wicket-keeper for the tour of Pakistan, has made it hard for him to play regular cricket.

By contrast, Warwickshire's regular wicket-keeper, Tony Frost, bats in the lower order.