Updated

Wal-Mart Stores Inc. (WMT) will pay more than $33 million in back wages to thousands of employees after turning itself in to the Labor Department for paying too little in overtime, according to an agreement announced Thursday by the U.S. Labor Department.

Wal-Mart said the department's review of its overtime calculations also found it had overpaid about 215,000 hourly workers during the last five years. The company said it will not seek to recover any overpayments.

Steven Mandel, associate solicitor in the Labor Department's Fair Labor Standards Division, said the case _ involving nearly 87,000 employees _ resulted from Wal-Mart coming to the department in early 2005 and asking for a review of its overtime calculations.

"They had some concern that some of the practices were not in compliance" with federal wage laws, he told a conference call for reporters

"It's not particularly unusual for an employer to come to us and talk to us about potential payroll violations," Mandel said.

Wal-Mart said in a statement that the settlement includes no fines or penalties and that it has adopted measures to prevent the errors from occurring again.

Mandel said the settlement was one of the largest ever reached by the department's wage and hour division.

Mandel said the department carried out a national review of all Wal-Mart stores over a two-year period from February 2005 to this year.

The settlement was approved Thursday by a federal judge in the U.S. District Court for western Arkansas, Mandel said.

The highest award to an individual employee was about $39,000, he said.