Bristol-Myers Squibb Co and Avista Capital Partners, a leading private equity firm, announced Monday that they have signed a definitive agreement for Avista to acquire Bristol-Myers Squibb Medical Imaging for approximately $525 million.

BMS MI is a leading supplier of medical imaging products for nuclear and ultrasound cardiovascular diagnostic imaging procedures.

"As Bristol-Myers Squibb continues to focus on evolving into a next- generation BioPharma company, we determined the best way to maximize the value of Medical Imaging for shareholders was to sell this business and reinvest the proceeds into our pharmaceutical research, development and commercialization efforts," said James M. Cornelius, chief executive officer, Bristol-Myers Squibb. "At the same time, we believe that Medical Imaging can maximize its potential under new ownership, and Avista has a proven track record of success in the healthcare field."

The transaction is expected to be completed by the end of January.

Bristol-Myers previously announced plans to close more than half of its manufacturing plants as part of a broad restructuring plan.