UnitedHealth Group's Optum health-services unit has agreed to acquire Surgical Care Affiliates (SCA) for about $2.3bn.

Surgical Care Affiliates will be acquired for $57 per share, with between 51% and 80% of the price coming in the form of UnitedHealth stock.

The transaction is expected to be closed in the first half of 2017.

SCA will be merged with OptumCare, Optum’s primary and urgent care delivery services business which works with more than 80 health plans.

The combined company will provide ambulatory care services and continue to expand SCA’s network of ambulatory care services and surgical hospitals in partnership with health systems, medical groups and health players.

At present, SCA and its affiliates offer their services to about 1 million patients every year in more than 30 states.

The combination is expected to work in unison, offering quality and value to patients and payers, while supporting doctors practising independently as eligible for surgical cases.

SCA chairman and CEO Andrew Hayek said: “Joining with OptumCare will enable us to better support and empower independent physicians, helping them provide high-quality care for their patients while making health care more affordable.

“The combination of SCA and OptumCare is another step forward toward our vision of becoming the partner of choice for surgeons.

UnitedHealth Group vice chairman and Optum CEO Larry Renfro said: “Combining SCA and OptumCare will enable us to continue the transition to high-quality, high-value ambulatory surgical care, partnering with the full range of health systems, medical groups and health plans."