Amgen, the world's biggest maker of biotechnology drugs, plans to sell its Fremont, Calif., development and manufacturing plant to Germany's Boehringer Ingelheim, the companies said on Tuesday. Financial terms were not disclosed.

Amgen, based in Thousand Oaks, Calif., said the 100,000-square-foot plant employs about 360 people who will become employees of Boehringer.

The German company, which has manufactured Amgen drugs on a contract basis for more than 10 years, said the deal will allow it to expand contract manufacturing, process development and development of active ingredients based on biologics.

The deal is expected to close in March.

Amgen obtained the Fremont facility in its 2006 acquisition of antibody drug maker Abgenix.