Simon Katich will be wearing just blue from now on © Getty Images

Australian batsman Simon Katich will not be returning to Derbyshire next season after turning down a new offer with the club. He doesn't feel he can commit to another 12-month cycle of cricket and wants to put his efforts into playing for New South Wales and aiming for an Australia recall.

During the 2007 season Katich has already scored 1780 runs in all cricket, while also leading the side during another tough season where success has been hard to find and David Houghton, the director of cricket, left midway through the summer.

"I have thought long and hard about this decision and it has been a difficult one for me to make," said Katich. "I have never played two back-to-back full seasons of county cricket and being captain of both sides would make it very difficult because you can't keep going at 100% the whole time."

Derbyshire's new head of cricket John Morris said: "I am obviously disappointed that Simon feels unable to come back next year due to the fact that he still has ambitions to play for Australia. As I have said before, I would have loved the opportunity to work with Simon next year as I know how good a player he is.

"He has never returned to England for a back-to-back second term with any of the other counties that he has represented in the past. Simon feels that if he is to achieve his ambition to one day play for Australia again, he needs to commit his future to New South Wales."

However, the club has agreed new two-year deals with Graham Wagg and Tom Lungley. Both players have passed 50 wickets for the first time in 2007, while Wagg has also provided useful late-order runs.

Wagg was one-year into his current deal, but 51 wickets and 431 runs has persuaded the club to offer him a longer and improved deal.