The US drugs giant is to spend $6m (£3.5m) redeveloping its 11-acre research and development laboratory in Moreton, Wirral.
The investment will provide new specialised laboratories for developing dosage forms and delivery systems for emerging medicines.
The decision safeguards 100 jobs and comes after a visit by two senior executives from the US, hosted by The Mersey Partnership earlier this year.
Dr Peter Timmins, director of biopharmaceutics research at BMS, said: "There are many reasons as to why Bristol-Myers Squibb has chosen to continue to significantly invest into the Wirral site, namely; the exceptional quality and availability of skilled staff, the innovation and spirit that exists among the pharmaceutical community in the region, the world class universities, the networking opportunities, the national and international connectivity, and the support received from The Mersey Partnership, Invest Wirral and the NWDA."
Bristol-Myers Squibb is a global leader in research and development activity with a mission of providing medicines for unmet medical needs.
Lorraine Rogers, chief executive of The Mersey Partnership, said: "Bristol-Myers Squibb is a world class business operating in a global market. Their investment in Wirral is highly significant for Liverpool city region's biomedical sector. TMP and Invest Wirral will continue to work closely with Bristol-Myers Squibb to support their future plans."