US review extended on broader use of Merck vaccine

* Gardasil is Merck’s cervical cancer vaccine

* Co wants to expand vaccine to women up to age 45

NEW YORK, June 16 (Reuters) - U.S. regulators have extended their review of Merck & Co's MRK.N application to expand the use of its cervical cancer vaccine to an older group of women, and are now expected to act by year end, the drugmaker said on Wednesday.

Gardasil is approved for use in girls and women ages 9 to 26 to protect against the human papillomavirus that causes cervical cancer. Merck has been hoping to broaden the use to women ages 27-45.

Merck had expected to hear from the U.S. Food and Drug Administration by next week, Merck spokeswoman Pam Eisele said.

“However, the FDA has informed us that the review cycle has been extended,” Eisele said. She said the company is continuing its talks with the agency, and expects to hear from the FDA by year end.

Gardasil was once thought to be a potential monster selling product for Merck, but sales have stalled amid competition from a rival GlaxoSmithKline GSK.L product and because many younger women have already been immunized with Gardasil, limiting the market size.

Reporting by Lewis Krauskopf, editing by Bernard Orr