The Children's Hospital of Philadelphia and RWJBarnabas Health in New Jersey announced Thursday that they had reached a preliminary agreement on an affiliation.

The letter of intent calls for a relationship that would be similar to those CHOP has with other community hospitals, such as Virtua Voorhees and Lancaster General, CHOP's chief executive Madeline Bell said.

"If you look at our overall strategy, it's to partner with other hospitals to help build their capability to care for children in their local community, in their hospitals, but to be connected to CHOP for those children who have more complicated care needs," she said.

RWJBarnabas, of West Orange, already operates the Children's Hospital of New Jersey in Newark, the Unterberg Children's Hospital in Long Branch, the Bristol-Myers Squibb Children's Hospital in New Brunswick, and Children's Specialized Hospital in Mountainside.

"They have a lot of pediatric services within their system," Bell said, "but they wanted somebody that could really help them build in certain subspecialties and geographic areas. They came to us, given the brand name that we have nationally but also regionally to help them do that. That's the plan."

RWJBarnabas was formed last year from the merger of Barnabas Health Inc. and the Robert Wood Johnson Health Care Corp. Combined, the two would have had $5 billion in revenue in 2015. CHOP had $2.5 billion in revenue in the year ended June 30.