The landscape for pharmaceutical employees has shifted again as Pfizer reportedly will lay off about 600 sales representatives in its primary-care division, according to Bloomberg News.

Pfizer, based in Manhattan, has a large facility in Collegeville that is part of the company's specialty-care division and is apparently not affected by this decision.

A Pfizer spokesman declined to confirm the number reported by Bloomberg but said in a statement: "As part of our strategy to allocate our resources, investments, and people to the areas that best serve our patients and customers, we continually evaluate how we can be more efficient and effective.

"As a result, we are making changes in some segments of our field force to better match the future needs of the business. Our U.S. field force is a valued resource that we remain committed to developing throughout this period of change."

Pfizer's top-selling cholesterol drug, Lipitor, was part of the primary-care division, but it lost patent protection last year, meaning there are now multiple competitors selling generic versions at lower prices. In the third quarter of 2012 alone, Lipitor revenue fell 71 percent from the same period in 2011.

Pfizer's overall third quarter revenue was $14 billion, a decrease of 16 percent compared with the same period in 2011. For the first nine quarters of 2012, revenue declined from $49.1 billion to $43.9 billion, a drop of 11 percent over the same period in 2011.

Pfizer acquired Wyeth (and the Collegeville facility) in 2009 and has been consolidating since at various speeds and in various ways. In 2011, Pfizer announced it was narrowing its focus in research and development to "areas with the highest potential to deliver value in the near term and over time," according to a U.S. Securities and Exchange Commission filing.

Earlier this year, Pfizer leased space in Collegeville to Dow Chemical. According to the SEC filing, through the first nine months of 2012, the company spent less on employee termination costs than it did in the same period in 2011. The 2012 figure was $424 million vs. $1.6 billion in 2011.