GM to swap U.S. manufacturing chief to new job amid truck launch DETROIT (Reuters) - General Motors Co (GM.N) said on Monday it is switching its head of North American manufacturing to a new position now that the U.S. automaker has begun building new versions of its highly profitable full-size pickup trucks. Diana Tremblay, 53, will assume the newly created role of global business services vice president and report directly to Chief Financial Officer Dan Ammann. The switch is effective July 1. Tremblay's switch to the new job comes at a critical time for GM, which has started selling the new 2014 Chevrolet Silverado and GMC Sierra trucks, vehicles that Citigroup Global Markets has estimated could generate an additional $1 billion in operating earnings in 2013 and 2014. The manufacturing rollout will continue through this year and into next as GM introduces different models of the big trucks and companion full-size SUVs. Edward Jones analyst Christian Mayes said the heavy lifting on the truck rollout likely has already been completed and top executives such as North American head Mark Reuss are still around to make sure the launch runs smoothly. "The team that (Tremblay) is leaving is very robust and they will put a strong leader in behind her to make sure that we meet the quality objectives and launch all those vehicles as well as we possibly can," GM spokeswoman Katie McBride said. Tremblay's skill set in manufacturing, where she has pushed the company to streamline and improve the process of building cars and trucks, translates well to the new job, McBride said. The focus in global business services will be on simplifying back-office processes and systems to improve speed, cut costs and free employees to focus on more meaningful work. Tremblay's new team will be comprised of employees from finance, human resources, facilities, real estate and purchasing. It will include thousands of employees and is expected to reduce associated costs by at least 30 percent over the next four years. McBride said a replacement for Tremblay will be named soon. Tremblay in July 2012 had her focus in manufacturing switched from global to North America, recognizing the importance of a preponderance of new-vehicle launches in the region, including the new trucks, GM said at the time. Her 36-year career at the company also included leading the team that negotiated the 2007 labor deal with the United Auto Workers union. Reporting by Ben Klayman in Detroit; editing by Matthew Lewis