General Motors Co. said Tuesday it laying off 510 workers at two Michigan auto plants that build cars in the face of low gas prices and falling demand for cars.

Late Tuesday, GM spokesman Bill Grotz told The Detroit News it will lay off 350 workers at its Lansing Grand River Assembly to “adjust plant production capacity to better align with market demand.”

That’s in addition to the phased layoffs of 160 of the nearly 1,470 hourly workers at its Orion Assembly plant in Orion Township in January that Grotz confirmed earlier in the day. Those layoffs will conclude by the end of 2015.

The Grand River plant builds the compact Cadillac ATS and ATS Coupe, and the midsize Cadillac CTS. Beginning in January, the Grand River plant will operate on a single shift until production of the next-generation Camaro starts. “We see these jobs coming back when production of the Camaro comes,” Grotz said in a phone interview. He would not say when the Camaro is expected to begin production.

Grotz said GM is committed to a strong and lasting presence in Lansing. “Since 2013, GM has announced $281.5 million in investment for Lansing-based facilities, including $174 million for a stamping plant … $44.5 million for a logistics optimization center and $63 million for Lansing Delta Township plant upgrades.”

Grotz said the layoffs at the Orion Assembly Plant are “to adjust plant capacity to better align with market demand,” Grotz said. The layoffs don’t impact the 170 salaried workers at the plant.

The production cuts at Orion Assembly will result in GM reducing capacity from 45 to about 37 cars per hour, about a 18 percent cut.

GM builds the Buick Verano and the subcompact Chevy Sonic at Orion. Verano sales were down 7.3 percent in October and down 6.2 percent this year to 37,391. Sonic sales fell 23 percent in October, but are still up 8.8 percent for the year to 83,210. GM has large supplies of unsold Sonic and Verano cars on dealer lots.

Orion Assembly also was down the week of Oct. 27 to complete scheduled maintenance and to manage production, according to a plant spokesman. The plant operates two shifts five days a week.

Representatives with UAW Local 5960 could not be reached for comment.

GM announced plans to close a dozen plants during its 2009 bankruptcy, including six in Michigan; it ultimately reversed its decision to close its Orion Assembly plant in Oakland County.

The automaker invested more than half a billion dollars in 2010 at Orion Assembly to retool for the Sonic and Verano.

Obama visited the Orion Assembly plant in October 2011 on a trip with South Korean President Lee Myung-bak to tout the U.S.-Korea Free Trade Agreement.

In 2012, the plant ran two, 10-hour shifts four days a week and turned out 825 vehicles a day.

DShepardson@detroitnews.com