John Middlebrook will become GM vice president of global sales, service and marketing operations and Mark LaNeve will replace him as GM North America vice president of marketing and advertising, from September 1.

"John's extensive experience in sales and marketing makes him particularly well-qualified for this new assignment," said GM chairman and CEO Rick Wagoner in a statement. "He will lead our efforts to implement best practices in GM's sales, service and marketing operations around the globe, and provide expertise and support to our four automotive regions to improve their capabilities in these critical areas."

LaNeve, divisional marketing general manager of Cadillac since 2001, will replace Middlebrook and report to John Smith, group vice president of North America vehicle sales, service and marketing.

"Mark's record of innovation at Cadillac, which has enjoyed a remarkable renaissance, makes him an ideal candidate to head GM North America's marketing and advertising operation," GMNA president Gary Cowger said.

Middlebrook, 63, began his GM career in 1959 at Oldsmobile. He moved to Pontiac in 1967, where he held a variety of leadership positions in sales, marketing, product planning and development. In 1981, he became director of passenger car planning for GM's worldwide product planning group, then returned to Pontiac in 1983 as assistant general sales manager of merchandising and operations. He was named Saturn's vice president in charge of sales, service and marketing in 1985, and in 1987 he was named a GM vice president in charge of the marketing and product planning staff.

Middlebrook became Pontiac general manager in 1989, general manager for Chevrolet in 1996, general manager for GMNA vehicle brand marketing in 1999, and GM vice president of marketing and advertising in 2000.

LaNeve, 45, joined Cadillac in 1981 and held several field assignments throughout the United States. In 1992, he was named director of sales promotions and was responsible for a variety of other marketing duties at Cadillac until 1996, when he was named a marketing director for Pontiac-GMC. LaNeve left GM in 1997 to take a post at Volvo Cars of North America Inc., and returned to Cadillac in 2001 as divisional marketing general manager.

GM also announced that Jim Taylor, 47, vehicle line executive of Cadillac prestige cars, will become divisional marketing general manager of Cadillac, replacing LaNeve, to whom he will report.

Mike DiGiovanni, 56, divisional marketing general manager of Hummer, will become executive director of strategic marketing, a new position, reporting to Smith. He will be responsible for leading the increased focus on intermediate to long-term strategies to support volume and share growth.

Susan Docherty, 41, will become divisional marketing general manager of Hummer, replacing DiGiovanni and reporting to LaNeve.

Docherty was Cadillac's marketing director for Escalade, Escalade EXT and Escalade ESV until taking a year out for a university course.