Pfizer could reduce its sales force by one-third, or 2,400 reps, according to a Bloomberg report that cited anonymous sources.

The layoffs would come ahead of looming patent expiries. Lipitor, the company’s blockbuster cholesterol drug, will face generic competition as early as 2011.

Bloomberg reported that Deutsche Bank analyst Barbara Ryan said in an interview last month that Pfizer CEO Jeffrey Kindler might detail new cost-cutting plans at an investor presentation on January 28. Ray Kerins, a company spokesperson, told Bloomberg that Pfizer’s plan is to “reshape our company into smaller, more focused units to best deploy our valuable resources and drive decision-making closer to our customers and to the markets in which we operate.”

On January 13, Pfizer announced plans to cut up to 800 research jobs in 2009. Those cuts represent 5-8% of the company’s approximately 10,000 researchers.