The logo of U.S. carmaker General Motors, or GM, is visible on the front grille of a GM Hydrogen 4 fuel cell-powered car at a presentation by Opel and GM on November 26, 2008 in Berlin, Germany. Sean Gallup/Getty Images

Several thousand General Motors (GM) employees will lose their jobs as part of a corporate slimming down operation, the automaker announced Monday. Several GM plants across North America will end production, which will result in 15 percent of the company’s salaried workers losing their jobs, according to USA Today.

GM’s press release did not say the plants were closing but said they were being “unallocated” due to "changing customer preferences in the U.S. and in response to market-related volume declines in cars." The following plants were included in Monday’s announcement:

Detroit-Hamtramck Assembly in Detroit, Michigan

Lordstown Assembly in Warren, Ohio

Oshawa Assembly in Ontario, Canada

Baltimore Operations in White Marsh, Maryland

Warren Transmission Operations in Warren, Michigan

The Detroit, Lordstown and Oshawa plants are all assembly plants, while the Baltimore and Warren plants are propulsion plants, per GM.

The plants could close permanently, per USA Today. There are around 5,600 employees at the Detroit, Lordstown and Oshawa plants alone, but GM said half of them will be given the chance to transfer to a different part of the company. Around 8,000 jobs will be cut in the U.S. in total.

Some of those workers will be offered buyouts and some will be laid off, according to USA Today.

GM’s latest earnings report in October included lower total car sales but higher average sale prices, which sent its share price in a positive direction, according to CNBC. Shares of GM rose roughly 5 percent on Monday at 2 p.m. ET.