DETROIT: Struggling General Motors is to part company with its North America head of advertising. The automaker says Mike Jackson (50) will not be replaced, his duties assumed by his boss, Mark LaNeve, vp-sales, service and marketing.

During his year-long tenure, Jackson (pictured) oversaw a seismic shift in some of GM's $2.3 million (€1.7bn; £1.16bn) North America ad business, including the Saturn marque's move from Omnicom Group's Goodby, Silverstein & Partners to Interpublic Group's Deutsch LA. The latter also snapped up corporate-branding work from its sibling McCann-Erickson.

Perhaps more significantly, Jackson steered GM's ad budget further in the direction of non-traditional online and digital media.

According to TNS Media Intelligence the car maker cut television spend by 16% last year to $1.38bn and slashed newspaper advertising by 60% to $232 million. Meantime, web spend rose 16% to almost $130m.

Before his move to Detroit, Jackson headed GM's glitzy regional marketing in Los Angeles and previously worked for Coors Brewing.

He will quit his post next month to "pursue other opportunities". He remains zip-lipped on the reasons for his resignation but some industry insiders have said he and LaNeve did not always see eye to eye.

The latter, however, was gracious about the departing executive saying: "Throughout his tenure, Mike has contributed to GM's improved product image, and brought a creative approach to GM's market presence."

Data sourced from Wall Street Journal Online; additional content by WARC staff