NEW YORK -- Tenet Healthcare Corp. said Thursday its hospitals will remain part of Humana Inc.'s networks a new four-year deal between the companies.

Tenet said its hospitals will be in-network for members of Humana'sMedicare, HumanaOne, health maintenance organization, point of service and preferred provider organization plans. Humana plan members will also have access to Tenet's diagnostic imaging centers, surgery centers, and urgent care centers.

Tenet said the deal took effect Wednesday.

Tenet is based in Dallas and it runs 50 hospitals and about 100 outpatient centers. Shares of Tenet rose 2 cents to close at $4.65 Thursday, and were unchanged after hours.

Humana is headquartered in Louisville, Ky., and it is one of the largest health insurers in the U.S. Its stock closed Thursday down $1.03 at $62.88 and were also unchanged in aftermarket trading.