He will leave in April this year, to take on a role at film production company.
In his six years at the company, he increased market share to double figures and played a key part in the launch of the Chocolate, Shine, Viewty and the Cookie.
Most recently, he arranged a partnership between LG Mobile with Twentieth Century Fox to support the launch of blockbuster movie Avatar via its new handsets.
The company also sponsors comedy on E4 and is running a series of sponsorship idents on the channel to promote its range of touch phones to 16- to 24-year-old viewers. The idents, created by Rainey Kelly Campbell Roalfe/Y&R, appear during shows The Inbetweeners, Big Bang Theory, Scrubs, One Tree Hill and Beauty and the Geek.
Prior to joining LG, Barton held senior positions at One2One and 3.
LG Mobile is currently lining up new Android and Windows handset offerings for 2010. A spokesperson for the brand said that Barton has not been replaced and the operator will begin looking for a successor shortly.