Llanelli Scarlets and Wales scrum-half Dwayne Peel has completed his move to Sale Sharks on a three-year contract.
Peel has won 59 caps for Wales and played three Tests for the Lions
The 26-year-old, Wales's most capped scrum-half and in the starting side to face Italy on 23 February, will join for the start of the 2008-09 season.
He said: "This is a chance to sample a new experience and a chance for me to play against different players."
The Welsh Rugby Union says players who play their club rugby outside Wales may harm their international selection.
Peel added: "I know four of the Sale Sharks players from the Lions tour of 2005.
"Sharks have some great players and I am looking forward to playing with them."
Sale director of rugby Philippe Saint Andre said: "This is excellent news for the club and the supporters.
"Together with Richard Wigglesworth we will have two young, international players covering the number nine position."
The departure of Camarthen-born Peel, a Grand Slam winner in 2005 and a scorer of five international tries, will "leave a void" at Stradley Park, said Scarlets chief executive Stuart Gallacher.
"Dwayne has served us admirably through one of the club's most thrilling decades," added Gallacher.
"He has been a cornerstone in helping us to develop a formidable European record in that time and in keeping us highly competitive in domestic tournaments."