Virtua, South Jersey's largest health system, said Wednesday that longtime president and chief executive Richard P. Miller will retire at the end of this year. The board has begun a search for his successor.

Miller, 64, was president and CEO of West Jersey Health System when it merged with Memorial Health Alliance to form Virtua in 1998, and he took the same positions with the new entity.

Among the highlights of Miller's tenure was the construction a $463 million hospital in Voorhees and the development of a string of outpatient and wellness centers in Sewell, Voorhees, and Moorestown.

In 2015, Virtua had operating profit of $99 million on total revenue of $1.3 billion. Despite a significant debt load, the system has a strong AA-credit rating from both Standard & Poor's and Fitch.