The 32-year-old's contract at Guinness Premiership side Saracens expires this summer, and he has opted against looking for another club.

'I am retiring,' he said. 'I have made the decision a while ago. My objective now is to give everything for the World Cup.'

After seven seasons at Sarries, Castaignede was expected to end his career in the Top 14.

But he feels he will be ready to quit after the World Cup, which is being held in France this autumn.

'I want to do something else,' he said. 'I have experienced some great adventures and some very good times.

'Yes, I could have played for another year, then another year. But at some time, you must know when to say stop.'

Before Saracens, Castaignede had spells at Castres and Toulouse, and has played 52 times for France.

He made his debut for his national team in 1995 in a clash against Romania, and has scored 17 tries since.

He did not play in this year's RBS 6 Nations Championship because of injury.

His versatility in the backs should secure him a place in Les Bleus' squad for the World Cup.