The world's No. 2 drugmaker by revenue also will switch from having dual US headquarters, in Philadelphia and in Research Triangle Park, North Carolina, to operating just the North Carolina headquarters.

US-traded shares of GlaxoSmithKline fell US$2.66 (S$3.95), or 6.6 per cent, to US$37.53 in early afternoon trading.

Spokesman Mary Anne Rhyne said on 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 related to the headquarters move, 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', Ms Rhyne said.

GlaxoSmithKline, the maker of antidepressant Wellbutrin and Requip for Parkinson's disease and restless legs syndrome, currently has about 8,500 US sales representatives, out of a total of 22,500 employees in the US 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 US sales representatives, for a net loss of 1,000 jobs, according to Ms Rhyne.

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 provide them with 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', Ms Rhyne said.

Workers losing jobs are being told this week and will be out of work by the end of the year.

Mr David Heupel, pharmaceuticals portfolio manager at Thrivent Large Cap Growth Fund, said GSK's move continues an industry trend 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. You're going to see plenty more of this as these businesses mature over the next several years,' Mr Heupel said, referring to patent expirations, pricing pressures from payers and other factors weighing on the revenue.

Edward Jones analyst Linda Bannister said besides those pressures and the lack of blockbusters coming to market anytime soon, drug companies also are concerned the new 'Democratic administration could push for lower prices'.

This year, companies from Bristol-Myers Squibb to Wyeth and even No. 1 drugmaker Pfizer have announced reductions in their US sales forces.

Just in the last six weeks, Merck and partner Schering-Plough have both done so.

'This is the new reality for the pharmaceutical industry', said Ms Bannister.

She said Glaxo might have made its cuts sooner, but new Chief Executive Andrew Witty just took over in May - and the company likely was hoping it could reignite growth of its diabetes drug Avandia and so would need more sales reps.

But last month, the American Diabetes Association and its European counterpart removed Avandia from their recommended treatments, and last week the consumer group Public Citizen urged US regulators to ban Avandia because of its link to several life-threatening risks, including heart and liver damage. -- AP