Penske Racing dumped talented but troubled driver Kurt Busch Monday.

Busch's NASCAR resume is impressive -- 24 victories and advancing to the Chase in six of its seven seasons -- but his behaviour at times has turned off sponsors.

There were reports Shell Pennzoil officials told Roger Penske they would continue their sponsorship only if Busch was dropped from the No. 22 Dodge.

Busch's recent incidents include one captured on YouTube in which he spewed profanities at a reporter and another where he gave a finger salute at the season finale.

"Leaving a great organization and a lucrative contract is not easy," Busch, 33, said in a news release. "But it's an important step for me and allows me to take a deep breath to work on things that can make me a better driver and a better person."