MILWAUKEE and CHICAGO — Aurora Pharmacy is slated to become part of a much larger organization.

Parent Aurora Health Care plans to merge with Advocate Health Care to form Advocate Aurora Health, which the companies said will be the nation’s 10th-largest nonprofit, integrated health care system. The combined entity will serve about 3 million patients annually.

Currently, Aurora Pharmacy has more than 70 locations in Wisconsin. Overall, not-for-profit Aurora Health Care serves over 1.2 million patients a year via a network of 15 hospitals and more than 150 clinics and 33,000 caregivers throughout eastern Wisconsin and northern Illinois.

“For the communities in Illinois and Wisconsin that we serve and for our two organizations, this is an unprecedented opportunity to shape our future and better serve patients,” Nick Turkal, president and chief executive officer of Aurora Health Care, said in a statement. “We are fortunate that our organizations are coming together from unique and complementary positions of strength, particularly at a time of evolving industry dynamics. Working together, we will deliver on the promise of value for the people who receive, provide and pay for health care.”

Under the merger pact, the combined organization will have a single board of directors, with an equal number of members from Advocate and Aurora. Turkal and Advocate Health Care chief executive Jim Skogsbergh will serve as co-CEOs. Aurora chairwoman Joanne Disch will chair the Advocate Aurora Health board during the first year of operation, and Advocate chairwoman Michele Richardson chair the board for the second year.

The Advocate and Aurora names will be retained, and each health system will maintain its current headquarters, the companies said.

Overall, Advocate Aurora Health will operate 27 hospitals, more than 500 sites of care, and employ over 3,300 physicians and nearly 70,000 associates and caregivers. Combined annual revenue is estimated at $11 billion.

“This merger is about transforming care delivery and reimagining the possibilities of health as bigger meets better and size meets value to benefit consumers,” commented Skogsbergh of Advocate, the largest health system in Illinois. “By joining forces, we will be able to expand our network to scale innovation and create a destination in the Midwest for patients and the talented clinicians who care for them.”

Pending state and federal regulatory review and approval, the transaction is expected to close by the middle of next year, the companies said.