The Carondelet Health Network of Southern Arizona today went from non-profit to for-profit and Texas-based Tenet Healthcare Corp. assumed majority ownership.

The switch took effect at midnight today, officials from Tenet confirmed.

The minority owners will be California-based Dignity Health and current Carondelet owners from Missouri-based Ascension.

Carondelet includes three Southern Arizona hospitals — the 486-bed Carondelet St. Joseph's and 400-bed Carondelet St. Mary's in Tucson and the 25-bed Holy Cross Hospital in Nogales.

The names of the hospitals will not change, Carondelet spokeswoman Lisa Contreras said.

Tenet officials this morning would not comment on whether any of the health network's 4,000 employees would be losing their jobs.

Officials from Tenet, Carondelet and Ascension also would not say what will happen to the Carondelet Foundation, a philanthropy that was created to support the work of Carondelet Health Network. The Foundation's most recent available 990 tax form listed its net assets in 2012 as $31.69 million.

A press release issued by the joint venture says Tenet will manage the operations of the network’s three hospitals, two physician groups, outpatient and ambulatory services, as well as other affiliated businesses in Tucson and Nogales, Arizona.

Tenet and Dignity Health separately own and operate hospitals and clinics in the Phoenix area and together manage a growing accountable care organization called the Arizona Care Network. The Tucson-based joint venture will connect Carondelet to the Arizona Care Network, the news release says.

The Arizona Care Network includes more than 750 patient care facilities across Tenet’s and Dignity Health’s Phoenix-based healthcare systems, with more than 3,400 providers and more than 200,000 covered lives.

The joint venture will maintain Carondelet’s Roman Catholic heritage and identity through an agreement with the Diocese of Tucson, officials say. Additionally, Carondelet’s existing charity care policies will remain in place, according to the news release.

Carondelet has a long history in the Tucson community.

The Sisters of St. Joseph of Carondelet opened St. Mary's - Arizona's first hospital - in 1880. St. Joseph's opened in 1961, and the nuns began managing Holy Cross in 1981.

Tenet Healthcare Corporation includes more than 125,000 employees and operates 83 general acute care hospitals, 19 short-stay surgical hospitals and more than 400 outpatient centers in the U.S., as well as nine facilities in the United Kingdom.

Dignity Health in Arizona includes five hospitals — Chandler Regional Medical Center, Mercy Gilbert Medical Center, St. Joseph’s Hospital and Medical Center, which includes Barrow Neurological Institute, St. Joseph's Westgate Hospital and Arizona General Hospital.

Ascension is a faith-based healthcare organization, the largest non-profit health system in the U.S. and the world’s largest Catholic health system.