Medical device maker ICU Medical said it would buy Pfizer's global infusion therapy business, Hospira Infusion Systems, for $1 billion in cash and stock.
ICU's shares rose about 7% to $135 in light premarket trading on Thursday.
Pfizer will receive $600 million in cash and nearly $400 million in newly issued shares of ICU Medical common stock, giving the drugmaker a stake of about 16.6%.
Pfizer will also get the right to nominate one director to ICU Medical 's board as long as the company maintains a 10% stake.
The deal is expected to close in the first quarter of 2017, the companies said.
Pfizer bought Hospira for about $15 billion in February 2015 to boost its portfolio of generic injectable drugs and copies of biotech medicines.
ICU Medical 's financial advisers are Barclays and Wells Fargo Securities, while Latham & Watkins is its legal adviser.
Pfizer's financial advisers are Goldman Sachs and Guggenheim Securities. Skadden, Arps, Slate, Meagher & Flom LLP and Ropes & Gray LLP are its legal advisers.