Chrysler said Elliott was leaving the company "to pursue other interests", the company is now in the process of naming a successor.
AM understands that Elliott is joining Volkswagen Group, possibly to head its Commercial Vehicles operation, and has asked Volkswagen for confirmation.
Elliott previously left as Chrysler UK MD in March 2006 to become CEO of Chrysler’s Chinese operations, but returned at the start of this year to help restore the American brand’s relations with its dealer network.
In the Winter 2007/8 National Franchised Dealers Association Dealer Attitude Survey, Chrysler was cast adrift at the bottom with an overall rating of 1.8 out of 10 – the worst ever score in the survey’s history.
Chrysler LLC Executive Vice President International Sales Mike Manley said: "Our business in the UK has grown well this year despite challenging market conditions.
"This growth is a credit to all of our employees in our UK sales organisation and the dedication of our dealers.
"This underlines the continued importance of the UK market to our international business.
"We would like to thank Simon and our UK employees for their contribution to this growth and we wish Simon well in his future endeavours."