Several communications staffers at Pfizer will exit the company in coming weeks as part of a restructuring effort, PRWeek reported. Ray Kerins, VP of external affairs and worldwide communications, will leave Pfizer this summer.

The company will merge Kerins’ external communications unit and the business communications team run by Mary Lou Ambrus, SVP of communications, according to a report  that originally appeared Friday (registration required). Ambrus will lead the newly combined practice and report to Sally Susman, EVP of policy, external affairs, and communications at Pfizer, according to a source close to the matter.

“As a world-class, global organization, we are dedicated to ensuing that our structure supports and advances the important businesses we service and this restructuring does exactly that,” Susman said in an emailed statement. Pfizer lost patent exclusivity for cholesterol drug Lipitor last November.

Kerins will stay on until June to support the company through the restructuring, Susman said, adding that she is “grateful to him for all his contributions to Pfizer, including the establishment of a truly high-performing media-relations team and social and digital team.”

Kerins said the split was amicable.

“I have nothing but praise and admiration for Pfizer, which plays such an important role in society,” he said. “I am extremely proud to have dedicated the last five years to Pfizer, developing innovative strategies to address some of the most challenging issues. I believe Pfizer is well positioned for the future.”

Kerins was named PR Professional of the Year at the 2010 PRWeek Awards.

Kristen Neese, senior director of external affairs at Pfizer, is expected to depart the company, a source close to the situation said. Chris Loder, senior director of worldwide communications, will stay with Pfizer, the source said.

Neese could not be immediately reached for comment.

The restructuring will occur as the pharmaceutical company reviews its relationships with its supporting agencies, including Ketchum and Edelman. It also recently released an RFP for its animal health division in an effort to promote the business as it seeks buyers, a source said.

The restructuring was in the works for months. The departures will occur as the drug company prepares to launch a campaign this summer to get consumers to embrace the idea of aging. After a search, SS&K won the account to work on that effort, according to a source close to the search.

SS&K did not immediately return a request seeking comment.

In an earlier restructuring of Pfizer’s communications team, it reduced the number of executives who report to Susman from 10 to seven.