Penguin Putnam has signed an agreement to buy Avery Publishing, of Garden City, N.Y., a notable publisher of diet, health and nutrition titles whose top seller, James Balch and Phyllis Balch's Prescription for Nutritional Healing, has sold more than five million copies. The deal, for which no figures were given, is expected to close by mid-October.

Rudy Shur, Avery's president and publisher, said the decision to sell had not been an easy one after 23 years, but added, "the decision was based on our strategy to enhance our position in the industry." He sees Penguin Putnam, with its strong presence in this market, as "a natural fit." Penguin Putnam president Phyllis Grann noted that Avery's 400-strong backlist, including many top sellers, would help her company to leadership "in this very rapidly expanding market."

A Penguin Putnam spokesperson said that Shur and the other Avery principals would remain for a six-month transition period. Meanwhile, John Duff, who heads Perigee Books, has been named publisher of the Avery imprint under Penguin Putnam. The company will also begin warehousing Avery's books next year.

Avery, born in the mid-'70s as a college publisher, quickly moved into the niche for alternative health books. It grew rapidly, and has been on PW's annual list of fastest-growing publishers since the list was launched in 1995. Total annual sales are estimated at around $17 million.