In the wake of Merck’s merger with Schering-Plough, the company is making staff cuts while hinting of more to come.

Five hundred employees from Schering-Plough’s former Kenilworth, NJ, headquarters were set to be let go this month, according to a post on the New Jersey Department of Labor website. It’s unclear in which part of the firm these cuts were to occur, though.

Employers in New Jersey are required by law to provide notice 60 days in advance of plant closings and mass layoffs.

Pfizer, which is in the midst of absorbing Wyeth, indicated plans to lay off 400 people in Monmouth Junction, the home of Wyeth’s research headquarters, according to the website.

Merck CEO Dick Clark commented on areas where he may authorize reductions.

“There is still a lot of duplication, not only in sales force but also in marketing organizations and corporate organizations and issues like that,” said Clark, speaking at a Goldman Sachs conference.

Merck has said it expects to eliminate 16,000 jobs as a result of the merger, which became final on November 4, 2009, with savings targeted at $3.5 billion.

Added to streamlining plans already in place by the two companies before their union, Merck is shooting for savings of about $6 billion after 2011.

Clark added that the firm will also consider outsourcing some of it sales needs, saying, “you may need flex in the system, particularly with the amount of launches we have planned on a global basis.”

Looking at other parts of the company, post-merger Merck now has 96 manufacturing plants.

“I think there’s an opportunity there,” Clark said, “just off the top of my head…that we’ll be able to consider.”