LAVAL -- Quebec-based Valeant Pharmaceuticals has a friendly deal to buy a U.S. company that recently received approval to market a drug that claims to improve sexual satisfaction for women with a certain condition called HSDD.

Valeant will pay about US$1 billion in cash plus a share of future profits to buy Sprout Pharmaceuticals, Inc., which has its headquarters in North Carolina.

Sprout got the U.S. drug regulator's green light on Tuesday to market its drug Addyi in the United States.

The companies say that the drug is a treatment for premenopausal women with HSDD -- hypoactive sexual desire disorder.

They says HSDD isn't due to medical or psychiatric issues, problems within the woman's relationship or the effects of other medication or drug substances.

Valeant expects Addyi to be available in the United States by the end of this year through certified prescribers and pharmacies and it's aiming to take the drug to international markets.

"Delivering a first-ever treatment for a commonly reported form of female sexual dysfunction gives us the perfect opportunity to establish a new portfolio of important medications that uniquely impact women," Valeant chairman and chief executive Michael Pearson said Thursday in announcing the deal.

Sprout also has the global rights to the sex drug, which Valeant expects to register for sale internationally.

The U.S. company, based in Raleigh, N.C., was created in 2011 as a spinoff of Slate Pharmaceuticals and has focused since then on treatments for premenopausal women with low sex satisfaction because of a condition called HSDD -- for hypoactive sexual desire disorder.

Sprout's chief executive, Cindy Whitehead, praised the "commitment and passion" of the comapny's 34 employees.

"This partnership with Valeant allows us the capacity to now ensure broader, more affordable access to all the women who have been waiting for this treatment," Whitehead said.

"Beyond building this in the United States, Valeant also offers us a global footprint that could eventually bring Addyi to women across the globe."

Valeant shares were little-changed in pre-market trading. They closed at US$244.91 on the New York Stock Exchange on Wednesday, and were up $1.09 after the announcement before trading resumed on Thursday.