Rhys Webb will sever his lengthy association with the Ospreys at the end of the season, reports Wales Online.
The Wales and Lions scrum-half is understood to have opted to join Toulon, ending months of speculation over his future.
His decision to leave Wales is set to be announced imminently.
He made his debut for Ospreys in 2007 after coming through the Bridgend ranks and played his first game for Wales in the 2012 Six Nations against Italy as a replacement.
Webb has won 28 Wales caps and scored a try off the bench for the Lions in the first Test defeat against New Zealand in June 2017.