Giant Eagle has added more medicines to a year-old program offering a month's supply of certain generic drugs for $4 in a move that officials say makes their list of low-cost prescriptions the longest in the country.

With more than 400 drugs now included, the O'Hara grocer appears to have topped the expanded offering announced by discount retailer Wal-Mart in late September. That plan covers about 360 products.

"We felt that it was important in our markets to be seen as a leader," said Randy Heiser, Giant Eagle's vice president of pharmacy. The company, which also is trying to improve its pricing image, paired the generic drug expansion with price cuts on more than 275 items in its health and beauty department.

Strong consumer reaction around the country to low-cost generic drugs has prompted a steady escalation in retailers' efforts to use them as a means of winning over customers.

Wal-Mart first began testing its program more than a year ago in Florida and has garnered much of the attention. Similar deals are available at chains such as Target, Kroger and Kmart. Meijer, a Michigan retailer that competes with Giant Eagle in some Ohio markets, just claimed it had given away one million free antibiotic prescriptions in a program that targets generics often used by children.

Although critics generally contend many deals don't cover newer, expensive medicines, some advocates argue the offers are helping cut prescription costs.

Twenty percent of all prescriptions filled at Giant Eagle stores are for medicines included in the $4 generic program, said Mr. Heiser. The company started its program last year with about 300 drugs.

In addition to adding some new classes of generic drugs to the original list, the grocer will begin discounting some drugs that it described as family planning, heart health and skin condition medicines. Those will run $9 a month, similar to programs now offered by other retailers.