Ochsner Health Systems and St. Tammany Parish Hospital formally launched their partnership Tuesday, calling the arrangement an “entirely new business model for the region.”

Ochsner, which earlier this year dropped a bid to run Jefferson Parish’s two public hospitals, is expanding its footprint on the north shore, especially in western St. Tammany Parish.

The partnership, first announced in May, will focus on making certain types of medical care, such as pediatrics and neurosciences, more widely available in the area. It also aims to expand cardiovascular and thoracic programs.

Under the agreement, St. Tammany Parish Hospital will retain its name, assets and employees. It will remain a public, nonprofit hospital governed by a publicly appointed board.

“Our partnership represents an entirely new business model for this region,” said Patti Ellish, the president and CEO of the St. Tammany hospital. The agreement will help reduce costs and improve quality and convenience of care, she added.

The two entities will work together to plan strategies for future growth and new facilities, services and specialties, said David Gaines, an Ochsner executive. That will prevent them from duplicating efforts and will make possible savings that can be reinvested in the systems, he said.

The hospital will also become a part of the Ochsner Health Network.

“It’s a forward-looking partnership that addresses the needs and changes of a community and the health care industry,” Gaines said.

St. Tammany Parish Hospital, the parish’s oldest hospital, has 222 beds in Covington. Slidell Memorial is the parish’s only other public, not-for-profit hospital.

Ochsner directly employs more than 900 doctors, and another 1,600 have admitting privileges. Of St. Tammany Parish Hospital’s approximately 400 doctors, only a small number are employees.

Ochsner purchased a full-service medical center in Slidell from Tenet Heathcare in 2010. It operates 11 clinics in the parish, five of them on the western side.

Follow Faimon A. Roberts III on Twitter, @faimon.