By LINDA A. JOHNSON AP Business Writer TRENTON, N.J. (AP) _ British drugmaker GlaxoSmithKline PLC is restructuring its U.S. operations, starting with reducing its U.S. sales force by 1,000, following many of its top competitors in eliminating sales jobs. The world’s No. 2 drugmaker, measured by sales, also will switch from having dual U.S. headquarters, in Philadelphia and in Research Triangle Park, N.C., to operating just the North Carolina headquarters. U.S.-traded shares of GlaxoSmithKline fell $1.94, or 4.8 percent, in morning trading. Spokeswoman Mary Anne Rhyne said Wednesday that the headquarters change is meant to eliminate confusion and is largely symbolic. There are currently no plans to cut jobs or close offices in Philadelphia, she said. “The goal is to build a business that’s more streamlined, that’s more customer focused, that meets the challenge of the current marketplace and is better prepared to manage the future portfolio of medicines,” Rhyne said. GlaxoSmithKline currently has about 8,500 U.S. sales representatives, out of a total of 22,500 employees in the U.S. It plans to cut about 1,800 sales rep positions, some of which currently are vacant, but at the same time beef up its vaccine sales force. The company expects to end up with a total of about 7,500 U.S. sales representatives, for a net loss of 1,000 jobs, according to Rhyne. She said there also will be an unspecified number of jobs cut among sales support staff, which includes sales management and workers who track sales representatives’ activities and make sure they have necessary supplies such as free samples and product brochures. “If you reduce your field staff, you can reduce the number of staff required to serve them,” Rhyne said. Workers losing jobs are being told this week and will be out of work by the end of the year. David Heupel, portfolio manager for pharmaceuticals and health care at Thrivent Large Cap Growth Fund, said GlaxoSmithKline’s announcement is a continuation of a trend across the industry to reduce expenses in areas from sales and marketing to supply purchases, manufacturing and even research and development. He said this right-sizing “is a healthy thing for the industry.” This year, drugmakers from Bristol-Myers Squibb Co. to Wyeth and even the No. 1 pharmaceutical company Pfizer Inc., have announced reductions in their U.S. sales forces. “You’re going to see plenty more of this as these businesses mature over the next several years,” Heupel said, referring to patent expirations, pricing pressures from payers and other factors weighing on the revenues pharmaceutical companies get from wealthy countries. Meanwhile, some drugmakers have said that they are beefing up sales staffs in emerging markets such as Brazil, Russia, India and China, where their revenue is growing and generic competition is sometimes less of a factor. Rhyne said that many of the functions in Philadelphia and Research Triangle Park are similar, covering fields such as accounting, communications, finance, human resources and information technology. There are about 5,000 employees in Research Triangle Park, spread over 35 buildings owned by GlaxoSmithKline there. The area in central North Carolina, bordered by the cities of Raleigh, Durham and Chapel Hill, is a major hub for pharmaceutical and biotech research. GSK leases its offices in downtown Philadelphia, where it has about 1,500 employees. The company also has research and development operations in Philadelphia’s western suburbs, on property straddling Upper Merion and Upper Providence townships. No cuts have been announced there.