Chicago-based Presence Health will join St. Louis-based Ascension to become part of AMITA Health under the terms of an agreement announced Thursday. The two entities had announced a non-binding letter of intent related to the deal in August.

AMITA Health is a joint venture of Ascension’s Alexian Brothers Health System and Adventist Midwest Health, part of Adventist Health System.

All Presence Health facilities will become part of AMITA Health except Presence Life Connections, which will join Ascension Living, Ascension’s senior care subsidiary.

“Joining Ascension and AMITA Health is a natural evolution for Presence Health given our shared mission, vision and values to provide quality, faith-based care,” Presence Health President and Chief Executive Officer Michael Englehart said in a statement. “We will continue to deliver quality care for our patients and residents, as well as provide additional clinical opportunities and patient care resources to all our physicians and associates.”

The transaction is expected to be finalized soon.

Ascension is the largest nonprofit health system in the United States and the world’s largest Catholic health system. It recently announced plans to form a new nonprofit generic drug company with three other healthcare organizations in consultation with the Veterans Health Administration.

Presence Health is the largest Catholic health system in Illinois.

Ascension Living was No. 8 on the 2017 LeadingAge Ziegler 150 list of largest not-for-profit senior living organizations. It has 25 communities in 10 states and offers levels of care including independent living, assisted living, memory care, rehabilitation and long-term care, according to its website.

Presence Life Connections owns 21 senior living communities and manages three more that offer levels of housing and care including affordable housing, independent living, adult day services, assisted living, memory care, skilled nursing and short-term rehabilitation, according to its website. Two of the communities are in Indiana; the rest are in Illinois. The company also offers home care and hospice services.