A jury in a Pennsylvania court determined Friday that Wal-Mart should pay workers at least $78.5 million for neglecting to pay its employees for extra hours they worked and for requiring them to work during rest breaks.

The class-action suit was brought by 187,000 current and former employees who worked for Wal-Mart between 1997 and 2006. The jury awarded about $2.5 million for the extra unpaid hours and about $76 million for the lost rest break time.

The lead plaintiff, Dolores Hummel, said she regularly had to work during rest breaks and after store hours to meet work demands, and estimated that she worked between 8 and 12 unpaid hours each month during her 10 years of employment at Wal-Mart. "One of Wal-Mart's undisclosed secrets for its profitability is its creation and implementation of a system that encourages off-the-clock work for its hourly employees," Hummel said in the lawsuit.

Hummel was allegedly fired after complaining about work conditions at Wal-Mart. After the jury's decision was announced, Hummel said that she and her fellow plaintiffs had brought the suit to show "how we were treated working at Wal-Mart--working off the clock and not getting paid."

Wal-Mart says it intends to appeal.

"Wal-Mart associates are the lifeline of our company, and it is our policy to pay every associate for every hour worked," the company said in a statement. "Any manager who encourages or even tolerates off-the-clock work or any other wage-and-hour violations is subject to discipline up to and including termination. Wal-Mart is committed to treating its associates fairly and in accordance with the law. The company has very clear policies on meal and rest breaks. In most instances, Wal-Mart's policies do more than is required by law."

Meanwhile, an attorney for the plaintiffs said he would seek an additional $62 million in damages from Wal-Mart, since the jury found that the retail giant had acted in bad faith.