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 by revenue also will switch from having dual U.S. headquarters, in Philadelphia and in Research Triangle Park to operating just the North Carolina headquarters.

"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," spokeswoman Mary Anne Rhyne said Wednesday

GlaxoSmithKline, the maker of antidepressant Wellbutrin and Requip for Parkinson's disease and restless legs syndrome, currently has about 8,500 U.S. sales representatives, out of a total of 22,500 employees in the U.S. and 100,000 worldwide. It plans to cut about 1,800 sales rep positions, some currently vacant, but at the same time beef up its vaccine sales force. The company expects to end up with about 7,500 U.S. sales representatives, for a net loss of 1,000 jobs, according to Rhyne.