The owner of Olive Garden and Red Lobster restaurants is putting more workers on part-time status in a test aimed at limiting the effects of upcoming health coverage requirements.

Darden Restaurants Inc. declined to give details but said the test was only in restaurants in four markets across the country. The test entails increasing the number of workers on part-time status, meaning they work less than 30 hours a week. Under the new health care act, companies will be required to provide health care to full-time employees by 2014. That would significantly boost labor costs.

About 75 percent of Darden’s employees are now part-timers.

Darden operates more than 2,000 restaurants in the United States and Canada, including LongHorn Steakhouse. It employs about 180,000 people.