(Reuters) - A California federal jury on Wednesday handed down a $55 million verdict against Wal-Mart Stores Inc WMT.N for failing to pay about 850 of its truck drivers all of the compensation to which they were entitled.

People talk outside a Wal-Mart Pickup-Grocery test store in Bentonville, Arkansas, June 4, 2015. REUTERS/Rick Wilking

The jury held that Wal-Mart owed the drivers backpay for conducting pre- and post-trip inspections, mandatory rest breaks and layovers between trips, but not for other tasks, such as fueling and washing trucks.

Current and former Wal-Mart truck drivers in California sued the company in 2008, claiming a plan that compensated drivers by mileage and activity rather than hours worked violated state law. Wal-Mart dropped the plan in 2015.

U.S. District Judge Susan Illston in San Francisco previously ruled that Wal-Mart violated California law for not paying its truck drivers minimum wage for all work performed. Illston left the determination of damages for trial.

Illston could double the jury award if she finds that Wal-Mart acted willfully.

Wal-Mart spokesman Randy Hargrove said the company disagrees with the verdict.

“We strongly believe that our truck drivers are paid in compliance with California law and often in excess of what California law requires,” Hargrove said, noting that its drivers’ average earnings range from $80,000 to more than $100,000 per year.

He said the company will be filing post-trial motions and is likely to appeal the verdict.

An attorney for the plaintiffs did not immediately respond to requests for comment.

The case is Ridgeway v. Wal-Mart Stores, U.S. District Court for the Northern District of California, No. 08-05221.