Thomas Jefferson University has finalized its agreement to acquire Einstein Healthcare Network, the two nonprofit systems said Friday. The initial deal was announced in March.

The acquisition of Einstein's hospitals — in North Philadelphia, Elkins Park, and East Norriton — will bring Jefferson's total to 18.

Jefferson had operating income of $12 million on revenue of $4.7 billion in the year ended June 30. Einstein had an operating loss of $19.6 million on $1.26 billion in revenue during the same period.

In a series of deals, Jefferson, based in Center City, has expanded its reach throughout much of the Philadelphia region. It acquired Abington Health in 2015 and Aria in 2016. Philadelphia University and Kennedy Health followed last year. In addition, Jefferson bought a controlling stake in Rothman Orthopaedic Specialty Hospital, in Bensalem. This year, Jefferson completed its deal for Magee Rehabilitation Hospital.

Jefferson did not give a timeline for completion of the Einstein acquisition, but said that with the definitive agreement in place the two systems will being working on obtaining regulatory approvals.