Dan Biggar is to leave Northampton with immediate effect and join French Top 14 club Toulon.
Saints announced last month that the Wales fly-half would depart Franklin’s Gardens at the end of this season.
But they have now confirmed his earlier-than-expected departure at the player’s request.
Biggar is not affected by Wales’ minimum 60-cap selection criteria for players plying their trade outside his country as he has made more than a century of Test appearances.
He captained Wales in last season’s Guinness Six Nations Championship and on their summer tour to South Africa, which included a first victory over the Springboks on South African soil.
Biggar, 33, is currently sidelined because of a knee injury and will miss Wales’ Autumn Nations Series campaign that kicks off against New Zealand on Saturday.
“As I said on the initial announcement of my departure, it has been a privilege to play for Northampton Saints and I have loved every minute of my time at the club,” Biggar said.
“I know this is a squad which can challenge for major honours this season, so this has been a very difficult decision for me to make. I move on with a heavy heart and I am grateful to the club for their understanding throughout the process.
“I never envisaged leaving Saints midway through the season, but this opportunity came around very quickly, and I made my decision with a long-term view in mind for my family.”
Saints chief executive Mark Darbon added: “Given the circumstances, with Dan’s contract ending at the end of the season, his availability for the rest of the current campaign, the multi-year offer to Dan from Toulon which was contingent on him moving immediately, and the quality of the up-and-coming fly-halves already at the club, we wanted to be pragmatic when Dan approached us.
“Dan is not just a world-class player, he is also one of the nicest blokes you could meet.
“He is someone who always did everything he could to help the club, on and off the pitch. So, we will miss him, but he departs with our very best wishes.”
