Tim Ambrose admits he will not make a harder decision in his career than the one which has seen him leave Sussex to join first division rivals Warwickshire.

The 22-year-old was today signing a three-year contract after being lured to Edgbaston with the promise of becoming Warwickshire's first choice wicketkeeper.

Frustrated at being understudy to Matt Prior, Ambrose let his contract expire at the end of the season and although Sussex offered him a new two-year deal, cricket manager Mark Robinson was always fighting a losing battle.

There were too many imponderables for Ambrose to consider staying at Hove. Prior may break through at international level this winter after being chosen for England's tour to Pakistan but he might not.

Although Robinson insists that Ambrose was good enough to play as a specialist batsman, he desperately wants to advance his career with the gloves.

Other counties - notably Yorkshire - were keen when it became apparent that he was open to offers but he was impressed by new Warwickshire coach Mark Greatbatch whom he met last week.

Nevertheless, cutting ties with the county Ambrose has played for since he was 17 and just arrived in England from Australia was not easy.

"It was a hard decision to make, probably the hardest I will ever have to make in my career," he said.

"Robbo, Chris Adams and, when he was here, Peter Moores, did everything they could but the one thing they couldn't offer was the one thing I wanted - the chance to keep wicket regularly.

Memories "It's a huge wrench. I've had five brilliant years and have some fantastic memories and made friends I hope will be friends for life.

"But career-wise this is a great move for me. Warwickshire have a new coach and a new captain coming so it's a new era up there and signing for three years gives me the chance to establish myself and build relationships."

Robinson is satisfied that Sussex did everything they could to keep Ambrose but, in his heart of hearts, he feared this day might come ever since it became clear, when both Ambrose and Prior joined the staff together in 2001, that Sussex had two special young talents on their hands.

"I think it was an unavoidable situation considering how talented they both are. Tim will go down in history because he helped us win our first Championship when Matt was quite happy to play as a batsman.

"But Matt's keeping has come on so much too and it has been hard for Tim. I've seen a lot of him in the past 18 months when I was second team coach and he is not a youngster any more. We saw in the last game of the season against Kent what a superb keeper he is.

"In all the years I've been here we have yet to lose anyone who has gone on to bigger and better things elsewhere but Tim could be the one.

"But he goes with our best wishes and we know that he hasn't gone for any other reason but to keep wicket."

Now the search for a new wicketkeeper, who could conceivably be first choice next season depending on Prior's England performances, is under way.

A handful of stumpers are on the market including Durham's Andrew Pratt, Nottinghamshire's David Alleyne and Derek Kenway of Hampshire.

But do not be surprised if Sussex make a move to bring Andrew Hodd back to the county from Surrey.