French flanker Patrick Tabacco has agreed to join Pau from Stade Francais on a three-year contract.
The 30-year-old, who has 16 international caps for France, will replace fellow international and Pau vice-captain Imanol Harinordoquy at number eight following his departure to join Biarritz next season.
"I discussed my future with (Stade Francais president) Max Guazzini on Sunday night," said Tabacco.
"We had not had the opportunity to do it before.
"Pau have been greatly interested in me. I am 30 and the offer was by far the best I got."
Wales' acting head coach Rob Howley has given Sam Davies and Rory Thornton a boost ahead of the RBS 6 Nations by naming the uncapped Ospreys duo in his largely experienced squad for the Autumn Internationals.