This article has been updated with comments from Quest.

Protein bars maker Quest Nutrition has filed a WARN notice signaling it plans to close two L.A. manufacturing facilities and lay off 524 employees.

The privately-held El Segundo-based company filed a Worker Adjustment and Retraining Notification Act notice Aug. 9 for the permanent closure of its City of Industry and Walnut facilities. Its City of Industry plant will begin laying off 402 workers effective Oct. 12, and the Walnut facility will lay off 122 workers starting Oct. 26, the firm said.

The move comes as the company shifts its manufacturing and distribution to third-party facilities, the company said.

“Moving to third-party manufacturing and distribution companies allows Quest to meet growing customer demand throughout the country and around the world by tapping into a specialized level of expertise in the food business that meets our products’ high-quality requirements, while offering improved distribution, infrastructure and logistical capabilities,” chief executive Dave Ritterbush said via email.

Quest Nutrition was founded in 2010 and makes various flavors of protein bars, catering its business primarily to the fitness industry. The company made $101 million in sales last year, according to Chicago-based IRI, a market research firm.

The company said it will maintain a distribution presence in California by utilizing a third-party warehouse in the state.

“Quest is committed to investing in the Golden State and will maintain our corporate headquarters in El Segundo, California,” Ritterbush said.

Manufacturing and trade reporter Shwanika Narayan can be reached at [email protected]. Follow her on Twitter @shwanika.