Wal-Mart has asked the U.S. Supreme Court to overturn a December decision by the Pennsylvania Supreme Court to approve a $151 million class-action award to employees in the state for unpaid wages and damages.

In 2006, a Philadelphia Common Pleas Court jury awarded Michelle Braun, a former employee, and nearly 188,000 other employees damages after some complained that the retail giant did not pay them when they worked off the clock or while they were supposed to be on breaks.

In its March 13 petition to the Supreme Court, Wal-Mart said the trial jury and Pennsylvania court decisions were wrong because the company had been subjected to "trial by formula," with a few plaintiffs' allegations applied to the whole group.

Wal-Mart wants the Supreme Court to follow the same logic it used in reaching a 2011 decision in favor of Wal-Mart in an oft-cited class-action sex discrimination suit.

That case, Wal-Mart Stores Inc. v. Dukes, turned on whether the entire class had common issues of law or facts and whether each worker should have to prove that worker's individual circumstance.

Wal-Mart argues in its petition that, like Dukes, the wage-and-hour case has important implications that go beyond the facts of the case and involve the adjudication of class action lawsuits.

The original wage-and-hour lawsuit was filed in 2002 in Common Pleas Court on behalf of Michelle Braun, a former employee, and others. Common Pleas Court Judge Mark I. Bernstein certified the class.

In 2006, the Philadelphia jury found that the company had properly handled the meal breaks but had deprived employees of pay when they worked during breaks or off the clock.

The case involved nearly 187,000 people employed by Wal-Mart from March 1998 through April 2006.

Wal-Mart's appeals through the Pennsylvania courts ended Dec. 15, with the Supreme Court's 4-1 approval of the jury decision.

"It is a sad commentary," said plaintiffs' lawyer Michael D. Donovan of Donovan Axler L.L.C., in Philadelphia, "that Wal-Mart's billionaire owners continue to believe that it is OK to short the wages of hourly workers, attempt to hide the evidence of the company's wage payment violations, and to then spend millions on frivolous appeals and harmful delaying tactics."

A Wal-Mart spokeswoman said in a statement, "We disagree with the Pennsylvania Supreme Court's decision, and continue to believe that these claims should not be bundled together into a class-action lawsuit. Most of these claims are over 10 years old. Wal-Mart has had strong policies in place to make sure all associates receive their appropriate pay and break periods. We have taken additional steps over the last decade, including enhancing our timekeeping systems and additional training, to make sure all our associates understand the importance of those policies and comply with them."