General Motors said Tuesday it was launching a peer-to-peer car rental service to allow owners to make money by listing them as shared vehicles.

The US auto giant said GM car owners would be able to list their vehicles via Maven, its car-sharing service in which the company offers hourly or daily rentals.

GM's new service will be entering the "sharing economy" in competition with peer-to-peer rivals like Getaround and Turo, which enable car owners to rent their cars using online platforms.

"Your car is one of the most expensive things you own. Sitting idle, it is a wasted asset," said Julia Steyn, vice president of General Motors Urban Mobility and Maven.

"It's time to put your car to work. Maven's peer-to-peer offering is a smart way for owners to offset their vehicle investment."

The new service is launching immediately in Chicago, Detroit and Ann Arbor Michigan with additional US markets in the coming months.

It will be integrated into Maven, the smartphone app rental service launched by GM in 2016 which has some 150,000 members.

GM said "peer cars" will be available alongside GM's own Maven cars for rental.

The website set up by GM indicates car owners will be able to set their own rental price, with GM providing insurance, satellite tracking via OnStar and keyless access. The owners will keep 60 percent of the rental fees.