EMD Serono finalizing expansion plans

EMD Serono Inc., which has 750 employees in Rockland and Billerica, is finalizing plans for a significant expansion at one or both of those locations, according to a company spokeswoman.

But the biotech company declined to provide additional details or say when it might publicly unveil the expansion plans. Massachusetts economic development officials also declined comment.

EMD Serono, based in Rockland, is a unit of German pharmaceutical company Merck KGaA.
(By Todd Wallack, Globe staff)