Nicky Peng has struggled for form after showing early promise

The 24-year-old joined the Welsh county at the start of the 2006 season from his native Durham, but has struggled to hold down a starting place.

"This season I have lost confidence and belief in my ability despite trying 100%," Peng told the club's website.

"It is not working for me or for the team and consequently I have stopped enjoying the game."

Great things were expected of Peng when he made his County Championship debut in May 2000 aged just 17.

Despite facing a strong Surrey bowling attack, Peng was hugely impressive as he amassed 98 for Durham and it was no surprise when he was called up by England Under-19.

It is best for me to play no more cricket and to have a break from the mind games which have affected me Nicky Peng

However, that early form deserted him and Peng moved on a two-year deal to Sophia Gardens in 2006 seeking a fresh start.

Although he has a high score of 158 in the first-class game and 121 in one-day cricket, Peng's batting average has never risen much beyond the mid-20s in both forms of the game.

"I feel at this moment that it is best for me to play no more cricket and to have a break from the mind games which have affected me," Peng added.

"I don't want to be dishonest with Glamorgan and therefore I have been completely open with regard to my frame of mind.

"I hope that my taking this decision will be helpful to the club in their planning for the rest of the season and beyond.

"I wish all of the players and everyone at Glamorgan only good things and my gratitude for their understanding."

Glamorgan chief executive Mike Fatkin said he was sorry that Peng has felt it necessary to take this drastic step, but supported the decision.

"We are all naturally disappointed to learn of Nicky's decision but we respect his honesty in explaining his reasons and the professional way in which he has gone about informing us," Fatkin said.

"On the basis that his mind is made up we would like to acknowledge his contribution and all of us at the club offer our sincerest best wishes for the future."