UPDATE 1-Merck loses Nasonex patent case

* Had filed suit against Apotex plan for generic Nasonex

* Merck says likely to appeal

By Nate Raymond

June 15 (Reuters) - Merck & Co, Inc lost a patent infringement lawsuit against Apotex Inc on Friday over Apotex's plans to market a generic version of the nasal allergy spray Nasonex.

U.S. District Judge Peter Sheridan in Trenton, New Jersey, dismissed Merck's complaint for patent infringement after finding it had failed to present sufficient evidence during a trial in April. The judge separately dismissed Apotex's counterclaim that Merck's patent was invalid.

"Today's decision reflects just one step in the lengthy patent litigation process, and we plan to review all of our options, including a likely appeal of the decision," Bruce Kuhlik, general counsel of Merck, said in a statement.

Elie Betito, a representative for Apotex, had no immediate comment.

Merck's Schering-Plough unit filed the lawsuit in December 2009 after the Apotex, a privately-held company in Canada, sought U.S. Food and Drug Administration approval to market a generic version of Nasonex.

The application sought to allow Apotex to market the generic version prior to the expiration of the patent at issue in the lawsuit, which is set to expire in April 2018. The FDA has yet to approve the application.

A bench trial was held April 2012. At trial, Apotex contended its nasal spray was different from Nasonex as the company intended to manufacture a version that did not contain water, unlike Merck's.

Merck had warned in its most recent quarterly report that an unfavorable decision in the Apotex case "would result in significant loss of sales in the U.S. market if generic versions become available."

Global sales of Nasonex were $1.3 billion in 2011 and $375 million in the first quarter of 2012. Nasonex had U.S. sales of $161 million in the first quarter, according to the company's May 8 quarterly report.