General Motors Co. is investing $175 million in a Lansing plant to build two of Cadillac's next-generation sedans.

GM, according to a spokeswoman, has already begun installing new tooling and equipment at the Lansing Grand River Assembly Plant, which now builds the Cadillac ATS compact and CTS midsize cars and Chevrolet Camaro.

The new Cadillac sedans — expected to be named CT5 and CT4 — will eventually replace the ATS, CTS and XTS large sedan in Cadillac's car lineup. GM plans to discontinue Cadillac ATS sedan output after the 2018 model year.

Production of the CT5 is expected to begin in 2019, followed shortly after by the CT4. The two cars are part of an extensive overhaul of the brand's lineup that will include a new vehicle, on average, every six months through 2021.

The latest investment comes two years after GM invested $211 million to support tooling and equipment and a 32,000-square-foot addition to the body shop for future Cadillac sedans.

GM has spent $464 million in manufacturing for Cadillac vehicles in the past two years. Other major investments have taken place to expand Cadillac Escalade capacity and build the first Cadillac XT4 and XT5 crossovers.

The new crossovers are expected to boost Cadillac's U.S. sales, which fell 8 percent in 2017. Globally, Cadillac sales — led by China — increased 16 percent to 356,467 last year.