The CEO of Amita Health, Illinois’ largest Catholic health system, is stepping down, a spokesperson confirmed Friday.

Mark Frey has served as CEO of Amita Health — a joint venture of Ascension’s Alexian Brothers, Adventist Midwest Health and Presence Health — since 2015 when Amita was created. Before that, Frey was CEO of Alexian Brothers, which joined Ascension in 2012.

“We thank Mark Frey for his many years of service and wish him continued blessings in future endeavors,” an Amita spokesperson said in an emailed statement.

While the health system giant searches for a new leader, both Karen Springer, executive vice president of performance optimization and nursing operations for Ascension, and Eddie Soler, executive vice president of finance for AdventHealth, will fill in as interim co-CEOs, the spokesperson said.

Frey had been leading Amita in integrating the 10-hospital Presence Health system after acquiring it in December 2018.

That same year, the Chicago City Council narrowly voted to approve a $5.5 million subsidy to Amita, but the health system later walked away from the funding without explanation in May.

The decision came two weeks after the Chicago Board of Ethics fined Ald. Edward Burke (14th) $2,000 for presiding over a January 2018 Finance Committee hearing where aldermen debated and approved the tax increment financing subsidy. Burke’s law firm had represented Amita on an unrelated matter within 12 months before the meeting.