TWAIN TOUR DRIVES WEDGE IN MARRIAGE!

SONGBIRD Shania Twain is reveling in her career comeback. But friends fear the workaholic country queen and her hubby, Frédéric Thiébaud, are leading separate lives — and hurtling toward a devastating $400 million divorce!

The Forever and for Always singer, 58, hit the road this year for a grueling but successful 78-date concert tour. But sources dish European-based businessman Frédéric, 53, has his own corporate commitments — and wasn’t always able to go gallivanting with his globetrotting wife of 12 years!

“He wants to spend quality time with Shania, but that becomes impossible when Shania is moving from city to city touring, and he can’t be there to hold her hand at every gig,” spills an insider.

“Their lives are partitioned, and that’s no way to have a successful marriage!”

The Man! I Feel Like a Woman! wonder tied the knot with the exec in 2011 after her first husband, producer Mutt Lange, left her for Marie-Anne Thiébaud — her former best friend and Frédéric’s then-wife!