Sports

Marcos Ambrose tells Richard Petty Motorsports he'll return to Australia at end of season

Driver Marcos Ambrose, of Australia, looks toward the outside from his garage during final practice for the NASCAR Sprint Cup Series auto race at Chicagoland Speedway in Joliet, Ill., Saturday, Sept. 13, 2014. Ambrose will leave NASCAR at the end of the season and return to his native Australia (AP Photo/Nam Y. Huh)

Driver Marcos Ambrose, of Australia, looks toward the outside from his garage during final practice for the NASCAR Sprint Cup Series auto race at Chicagoland Speedway in Joliet, Ill., Saturday, Sept. 13, 2014. Ambrose will leave NASCAR at the end of the season and return to his native Australia (AP Photo/Nam Y. Huh)  (The Associated Press)

Marcos Ambrose has informed Richard Petty Motorsports he will leave NASCAR at the end of this season and return to his native Australia.

The announcement Saturday comes amid mounting speculation that Ambrose will join Roger Penske as the team enters prepares to enter Australia's V8 Supercar Series. Penske acknowledged in July he was "looking at the opportunity" to work with Ambrose in Supercars.

RPM wanted Ambrose back in the seat of the No. 9 Ford and said his future with the team was in Ambrose's hands. Ambrose has been with RPM since 2011, and has two wins and 44 top-10 finishes.

He had a shot to make the Chase for the Sprint Cup championship field at Watkins Glen, but finished second.