London Wasps will begin their Amlin Challenge Cup campaign without Shaun Edwards.
Edwards has left Wasps, who face Bayonne, Bordeaux-Begles and Rovigo in Pool 3, by mutual consent having spent 10 years at the club.
The former rugby league great guided Wasps to Heineken Cup crowns in 2004 and 2007, with victories over Toulouse and Leicester Tigers securing Europe's greatest prize at Twickenham.
He has held the roles of backs coach, defence coach and head coach during his decade in black and yellow and will be fondly remembered for also securing an Amlin Challenge Cup, two English Premiership titles and an Anglo-Welsh trophy since switching codes in 2001.
"Shaun is rightly held in great esteem and high affection by everyone associated with the Club and he is leaving a massive legacy here," said Club director Lawrence Dallaglio, who skippered Wasps to both their Heineken Cup triumphs under Edwards.
"He has developed into one of the most highly respected coaches in world rugby and both the Club and Shaun himself feel that now is the right time for him to go on and continue to develop himself as a coach in another environment and perhaps at a higher level.
"We have no doubt that Shaun's reputation, greatly enhanced by his work with Wales at the recent World Cup, will present him with many opportunities at the top level of the sport and he departs from Wasps with the best wishes from everyone at the Club."
Edwards has been coaching on the international stage with Wales since 2008 after Wasps allowed him to combine club with country, while he assisted Sir Ian McGeechan on the British & Irish Lions tour of South Africa in 2009.
His contract with the Welsh Rugby Union expired after the third-place play-off defeat to Australia and he has since been heavily linked with a number of posts, including a position with England.
Edwards is refusing to be drawn on such speculation, however, but he does admit that he feels ready for a new challenge.
"I would like to thank the supporters, sponsors, fellow coaches and owners of London Wasps but most of all the many great players who I have had the privilege to coach in my 10 years at the Club," said Edwards.
"I will always have fond memories of my time with Wasps and feel ready and excited for some new challenges ahead of me.
"The experiences of the recent British and Irish Lions tour and the recent World Cup have given me more knowledge than I have ever had."
The directors of ERC voted unanimously at a Board meeting to postpone all decisions including the release of further instalments of ERC's distributable central revenues to the six shareholder countries until 19 February next when the Board will meet again to reconsider the issue.