By Ransdell Pierson

The world's biggest drugmaker, which recently narrowed its sights to 10 disease areas and dropped its long-standing focus on heart research, said the layoffs will be at laboratories in St. Louis, Groton, Conn., La Jolla, Calif. and Sandwich, England.

"It's part of Pfizer's overall plan to refocus research in a more efficient way; we're taking a methodical approach to hit our goals," company spokesman Ray Kerins said of the job cuts.

Pfizer did not disclose how much savings the layoffs might generate or whether additional research jobs could be targeted next year and beyond.

"We're in a strong financial position, with a strong balance sheet," Kerins said.

But company revenue fell in the third quarter amid declines for Lipitor and drugs for blood pressure, cancer and allergies now competing with generics.

The New York-based company has already cut more than 25,000 jobs since 2004, or about a quarter of its overall global workforce, in an attempt to cut costs and generate earnings growth, despite generic competition for many of its major medicines.

Pfizer's biggest challenge comes in 2011, when its Lipitor cholesterol drug faces competition from cheaper generics.

Earnings growth has been anemic and shares of the company are trading at 10-year lows, despite belt tightening and the promotion in mid-2006 of Pfizer's general counsel Jeffrey Kindler as chief executive.

Disappointing clinical trials have forced the company to scrap a number of once-promising experimental drugs, including a cholesterol medicine called torcetrapib that Pfizer hoped would become a $10 billion-a-year product that could help offset expected plunging Lipitor sales.

The company is counting on Martin Mackay, a longtime Pfizer executive who was promoted to research chief in late 2007, to deliver the kinds of big products that have eluded its laboratories over the past decade.

Mackay, speaking on Tuesday at a JP Morgan healthcare conference in San Francisco, highlighted experimental treatments for cancer, arthritis and Alzheimer's disease and said Pfizer was on track to file 15 to 20 marketing applications for drugs between 2010 and 2012.

Other hard-pressed large drugmakers have also cut thousands of jobs to deal with slow sales of medicines and generic competition.

Bristol-Myers Squibb Co said in December it would cut another 10 percent of its sales force by 2010. Two months earlier, London-based GlaxoSmithKline Plc said it would cut up to 850 research and development jobs in Britain and the United States, equivalent to around 6 percent of the company's overall R&D workforce.

(Editing by Andre Grenon)