The private-equity firm KKR has taken a big stake in the medical- and dental-supply company Henry Schein and plans to work with the company to improve its operations. KKR has amassed a large stake in the company and announced a deal Wednesday that includes increasing that stake to 12% with the option to buy up to 2.

Private equity firm KKR has taken a large stake in Henry Schein and reached a deal to add members to the company's board, the distributor of medical products said on Wednesday. Shares of Henry Schein were up more than 3% at $78.

KKR & Co. has taken a 12% strategic stake in Henry Schein Inc and will work with the company to improve operations at the world’s largest distributor of medical products to office-based dentists and doctors.