Jamie Robinson has spent a decade with the Cardiff Blues
Wales centre Jamie Robinson will quit Cardiff Blues at the end of the season to take up a two-year contract with French club Toulon.
Robinson, 28, has spent 10 years at the Arms Park but has slipped down the pecking order at the Blues.
But the Welsh region have announced the signing of Australia utility back Sam Norton-Knight from the Waratahs.
"This has been the most difficult decision I've had to make in my life so far," Robinson said.
"I'm eternally grateful for the support both Cardiff RFC and the Cardiff Blues have given me over the last 11 seasons and also the fantastic support of the fans at the Arms Park.
"I grew up in Cardiff, played for both Cardiff Schools Rugby and Cardiff Youth, graduated from the University of Glamorgan and have never experienced club rugby outside of Cardiff.
"I feel at this point in my career that I would benefit from a new challenge and also a complete change of lifestyle and I feel moving away from Wales that Toulon can certainly offer me this."
Robinson, who has won 23 Wales caps, is understood to have been offered a new contract by the Blues.
But the centre, whose fly-half brother Nick is still at the Arms Park, has seen the partnership of Tom Shanklin and Jamie Roberts limit his starts at both regional and international level.
Blues director of rugby David Young said: "Working with and watching Jamie develop over the past seasons I am naturally saddened that he has decided to leave, particularly with such an exciting time ahead.
"However, I understand his desire to experience another and very different rugby culture and on behalf of us all I wish him well with his time with his new club in France."
Robinson will link up with Sales Sharks director of rugby Philippe Saint-Andre, who is due to join Toulon in the summer.
The Blues' ranks will be bolstered by the addition of Norton-Knight, 25, who is at home playing anywhere along the backline but has been playing regularly at full-back.
But the twice-capped Wallaby, who is understood to have agreed a three-year deal with the Blues, has made no secret of his desire to play regularly at fly-half.
That could see him go head-to-head with Nick Robinson for the Blues number 10 shirt.
However, the Blues fly-half is thought to be a target for English clubs Sale, Worcester and Gloucester.
"I enjoy playing full-back [for the Waratahs]," Norton-Knight has previously said.
"I am not bitter about that or anything, but I would still like to give myself a bit of a test at 10. So that is really what the move is about."
Norton-Knight's departure to Wales could pave the way for the Waratahs to recruit full-back Drew Mitchell from the Western Force.
But Young is delighted to have captured another highly-rated player from the southern hemisphere, with the likes of New Zealanders Ben Blair, Paul Tito and Xavier Rush already on board.
"Sam is unquestionably a quality signing who has generated significant interest from many other parts of the globe and we are delighted he has chosen to come to the Blues," Young said.
"He is already an experienced player at a relatively young age with a fine level of maturity to his game.
"His versatility is a real bonus to our squad and we look forward to him becoming an important member of our squad next season."