Jamie Roberts and Dan Lydiate will move to French club Racing Metro when the season ends, BBC Wales Sport has learned.
The Wales internationals have already announced their intention to leave Welsh regions, but have not revealed their destinations.
Paris club Racing have long been linked with the pair but the deals will not be officially announced until May.
Ireland fly-half Jonathan Sexton is also expected to join the French club.
The 27-year-old, who has won 36 caps, will reportedly be the highest-paid player in French rugby next season when he moves from Leinster.
Racing are bankrolled by multi-millionaire owner Jacky Lorenzetti, who is intent on building the strongest team in Europe.
Newport Gwent Dragons flanker Lydiate and Cardiff Blues centre Roberts have been targeted by a host of leading clubs since deciding not to renew their contract with their regions.
Lydiate, 25, was named the player of the tournament as Wales clinched the Six Nations Grand Slam in 2012, but an ankle injury prevented him from adding to his 27 caps in this season's campaign as the champions retained their title.
He recently returned to action in a late bid to earn selection for the British and Irish Lions tour of Australia this summer.
Roberts, who has won 53 caps, rose to prominence during the last Lions tour in South Africa fours years ago, where he won the player of the series award.
The pair will add to the already significant Welsh contingent playing in French club rugby, which includes Bayonne's Mike Phillips and Perpignan's James Hook.
Also leaving Wales at the end of the season is Grand Slam winner George North, who will swap Scarlets for Northampton Saints in the English Premiership.
Gethin Jenkins is returning to Wales to re-join the Blues, though, after just one season with Top 14 leaders Toulon.
The impending loss of North from the Welsh game, adding to the other high-profile exits, sparked the current antagonism between the four regions and the Welsh Rugby Union.
Both sides want changes to ensure the best players stay in Wales, but there has been little progress or even discussion over recent weeks on possible solutions.