Pfizer has indicated that about 350 jobs will be preserved at its research and development centre in Sandwich.
The company announced plans to phase out the Kent facility earlier this year, but has now revealed its intention to retain a partial pharmaceutical sciences operation on the site.
Pfizer will continue with its plan to vacate the remainder of the centre, which has been renamed Discovery Park in a bid to attract new occupants, by the end of 2012.
Meanwhile, the firm's Dr Annette Doherty is due to take over from Dr Ruth McKernan as site director.
In a statement, the pharmaceutical giant said its decision to retain a presence in Sandwich was made following a "rigorous diligence process".
A company spokesperson explained: "Pfizer determined that retaining a portion of its pharmaceutical sciences operation at Sandwich presents the best solution at this time for Pfizer's business."
The firm's announcement was welcomed by Kent County Council and David Willetts, minister of state for universities and science.