Jan. 13 (Bloomberg) -- Wal-Mart Stores Inc., the world's largest retailer, will begin an advertising campaign to counter criticism that it pays workers too little.

The company is taking advertisements out in more than 100 newspapers starting today, spokeswoman Mona Williams said.

The ads will focus on issues raised by critics of its wages and benefits programs, Williams said. Wal-Mart, based in Bentonville, Arkansas, last June redesigned its wage structure to boost salaries for some workers amid criticism by labor unions and other opponents of the retailer's expansion that Wal-Mart pays workers less than local prevailing wages.

Concerns about labor policies and a class-action suit claiming that Wal-Mart paid and promoted women less than male workers have restrained the stock price, said analysts, including Emme Kozloff at Sanford C. Bernstein. The retailer also faced its slowest sales gains in more than a decade last year as low-income shoppers pared budgets amid higher energy prices.

Shares of Wal-Mart rose 49 cents to $54.08 yesterday in New York Stock Exchange composite trading. They declined less than 1 percent last year, the third annual decline in five years. From 1981 to 1999, the stock declined in only three years.

The Standard & Poor's Supercomposite Retailing Index, which doesn't include Wal-Mart, gained 21 percent last year.

The advertising campaign was reported earlier by USA Today.

Slower Sales

Some shoppers were discouraged during the holiday season when Wal-Mart initially offered fewer discounts the day after Thanksgiving, said investors including Patricia Edwards, who helps manage about $5.3 billion at Wentworth, Hauser & Violich in Seattle. Sales at U.S. stores open at least a year rose 3 percent in December and 0.7 percent in November.

Consumers may also have turned to other retailers after reading criticism of Wal-Mart's labor issues, said David Keuler, who helps manage about $60 billion at Mason Street Advisors including Wal-Mart shares.

``People aren't overlooking the image that Wal-Mart has just to get a bargain,'' with the economy getting stronger, said Keuler, who is based in Milwaukee.

Unions including the United Food & Commercial Workers have said Wal-Mart pays its workers less than those at other supermarkets and doesn't provide adequate health-care benefits.

Wal-Mart's average hourly wage for full-time employees at its discount stores is $9.99, in addition to contributions to 401 (K) and profit-sharing plans, spokeswoman Sharon Weber said. The company in June also said officers' bonuses may be cut if some diversity goals aren't reached.