Wal-Mart Stores, the nation’s largest retailer, said Tuesday that it would pay up to $640 million to settle some 63 wage-and-hour lawsuits that accused it of forcing employees to work off the clock and go without meal and rest breaks.

Some of the cases date back to 2000.

“Many of these lawsuits were filed years ago and the allegations are not representative of the company we are today,” Tom Mars, executive vice president and general counsel for Wal-Mart Stores said in a statement.

The cases, which were brought by different groups of lawyers in various states, involved hundreds of thousands of current and former hourly employees. The total amount to be paid will depend on the number of claims submitted, but it will be at least $352 million, Wal-Mart said.

Several lawyers said Wal-Mart had reached the settlement to help turn an embarrassing page as its current chief executive, Lee Scott, turns the job over to Michael Duke.

David Nassar, of Wal-Mart Watch, a union-financed advocacy group, said: “They’re throwing this weight overboard to lighten their load.”

Frank Azar of Franklin D. Azar & Associates, co-lead counsel in 14 states, said in a statement Tuesday that he was pleased with the settlement and thought it was fair.

“We are equally pleased that Wal-Mart has made tremendous strides in wage and hour compliance,” Azar said, “and that it has implemented and agreed to continue to follow state of the art compliance programs so that these improvements will continue into the future.”

Wal-Mart announced the settlement less than two weeks after it reached a $54.25 million settlement covering 100,000 current and former employees in Minnesota who asserted they were due money over missed breaks and off-the-clock work.

In a case still pending, Wal-Mart has appealed a 2005 verdict in which a California jury ordered the retailer to pay $172 million for making employees miss meal breaks.

In 2006, a jury in Pennsylvania awarded $78 million against Wal-Mart in a lawsuit over rest breaks and off-the-clock work. Last year, a judge increased that award to $188 million to include damages, interest and lawyers’ fees. Wal-Mart has also appealed that ruling.

The dozens of wage-and-hour lawsuits have accused Wal-Mart and its managers of various illegal stratagems, among them forcing employees to work unpaid off the clock, erasing hours from their time cards and preventing workers from taking their lunch breaks and rest breaks.

Robert Bonsignore of Bonsignore and Brewer, co-counsel in a group of 35 cases consolidated in Nevada and cases covering four other states, said that as a result of the settlement, “Wal-Mart can now say that it has taken action to make its stores a great place to shop and work.”

Wal-Mart said it expects a related after-tax charge from continuing operations in its fiscal fourth quarter of about $250 million, or 6 cents a share.