LITTLE ROCK, ARK. ? Wal-Mart Stores Inc. chief executive Lee Scott led a media charge Thursday to counter criticism that the world’s largest retailer is a behemoth that takes advantage of its workers and stifles competition.

Scott said he wanted Wal-Mart workers to know the company was speaking up for them. He also wants Wal-Mart to have a better handle on how it is perceived among members of the public.

The company is pushing its message of providing opportunity for advancement and that its stores provide mainly full-time jobs that come with a broad benefits package.

“We want to get those myths off the table, set the record straight,” Scott said in a phone interview. He was in New York City for a round of media interviews.

But a union critic of the discount chain said Thursday the company was ignoring social costs created by its megastores. The United Food and Commercial Workers Union said Wal-Mart was bending the truth.

Wal-Mart may count about three-fourths of its workers as full time, union spokesman Greg Denier said, but those employees don’t get full 40-hour weeks.

He said the health insurance the company touted was too expensive and did not provide enough coverage for illnesses that are short of catastrophic.

Wal-Mart has 1.2 million employees in the United States, making it the nation’s largest private employer. Wal-Mart gives communities stable jobs, Scott said, and workers have advancement opportunities and benefits that include stock purchase, a 401(k) retirement plan, discount cards and other benefits.

Scott said the company wanted to take its message directly to its customers and their communities.

“Customers trust us, and they want to know their trust is well placed,” Scott said.

That’s true of some Wal-Mart shoppers but not most, said Jim Rice, chief credit officer at Bernard Sands Retail Performance Monitor in New York.

“I don’t think a majority of shoppers pay attention to either the charges or to Wal-Mart’s defense,” Rice said. “If Wal-Mart has good selection and good prices, they’ll keep shopping.”

Rice said Wal-Mart was right to respond to its detractors.

“Any time you don’t answer (criticism), you’re going to suffer damage,” Rice said, noting Wal-Mart often had let its critics speak and not mounted a defense. “This will have a positive effect.”

Rice said the message from Wal-Mart would help rally employees, and could resonate in communities where Wal-Mart wants to expand.

The company has sought to add a second store in Lawrence, but its plans for the northwest corner of Sixth Street and Wakarusa Drive have been embroiled in zoning disputes and legal wrangling for months, as city officials have denied developers building permits amid outcry from vocal opponents.

Wal-Mart failed in an attempt last year to put a store in Inglewood, Calif., where the retailer lost a referendum. Critics painted the company as an unwanted source of traffic and low-paying jobs. There is a move in some cities to limit Wal-Mart, Target Corp. and other big box retailers because of the sprawl they bring.

Scott said the criticism from so many different directions had swallowed Wal-Mart’s central message.

“I liken it to being nibbled to death by guppies,” Scott said.

Wal-Mart Stores Inc. fell 44 cents Thursday to close at $53.64 on the New York Stock Exchange, as most stocks were pressured by higher oil prices and concerns over the economy.