It operates services as part of the Adelaide Metro network under contract to the Government of South Australia.

It is a subsidiary of Keolis Downer, and is a separate business to its sister company LinkSA, which operates buses in regional South Australia.

In April 2000, Australian Transit Enterprises won a contract put out to tender by the Government of South Australia to operate its Adelaide Metro Outer South services, with 82 buses.

Australian Transit Enterprises also formed a joint venture with the government's TransAdelaide to operate the Hills area services under the Transitplus name (separate to SouthLink).

In April 2005, SouthLink began operating the Outer North Adelaide Metro contract that had previously been run by Serco.