UPDATE 1-Forest, Daiichi to co-promote hypertension product

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NEW YORK, Aug 21 (Reuters) - Forest Laboratories Inc FRX.N will help promote Daiichi Sankyo Co Ltd's 4568.T experimental hypertension drug Azor in the United States, the companies said on Tuesday.

Forest will pay Daiichi Sankyo $20 million up front and will receive an annual co-promotion payment based upon U.S. product net sales, the companies said.

Daiichi Sankyo in November 2006 filed an application seeking U.S. approval for Azor, which combines two other anti-hypertensives into one drug.

Azor incorporates amlodipine besylate and olmesartan medoxomil, which are respectively the main ingredients in Pfizer's PFE.N Norvasc and Daiichi Sankyo's Benicar.

Forest has been promoting Benicar in the United States.

In the six-year Azor agreement, Forest and Daiichi will co-promote the drug during the first three years followed by a three-year period of residual payments to Forest from Daiichi during which Forest will no longer co-promote the product.

Forest is trying to shore up its line of medicines in advance of losing U.S. patent protection for its top products -- the Lexapro antidepressant and Namenda Alzheimer’s drug -- in the coming years.

Reporting by Lewis Krauskopf