AstraZeneca has settled a legal fight over its top-selling cholesterol drug Crestor with generics companies, protecting revenues in the all-important U.S. market until 2016.

Under the agreement, Watson and Egis concede that the Crestor substance patent is valid. The settlement allows Watson to begin selling a generic version of Crestor on May 2, 2016, at a fee to AstraZeneca of 39 percent of net sales, until the end of pediatric exclusivity on July 8, 2016.

AstraZeneca said on Monday its partner Shionogi <4507.T> was also a party to the settlement agreement.

(Reporting by Ben Hirschler)