The appointment of the Rev. Juan Antonio Guerrero Alves, a 60-year-old Spanish economist, came one day after Australia's Supreme Court agreed to hear Pell's appeal of his conviction for molesting two choirboys in the 1990s. Pell denies the charges.
Francis created the Secretariat for the Economy, and named Pell its prefect, as a key part of his financial reform plans after being elected pope in 2013. Pell had tried to wrestle the Holy See's opaque finances into order and align them with international standards, but his efforts and brusque style were rebuffed repeatedly by the Vatican's old guard.
Like Pell, Guerrero is a relative outsider to the byzantine world of the Vatican bureaucracy but his Jesuit credentials should at least send a signal that he enjoys the full trust of Francis.
He comes to his new job in a period of financial crisis, after Vatican prosecutors raided the secretariat of state and the Holy See's financial watchdog last month after receiving reports of a suspicious real estate transaction.
No charges have been lodged, but the raids and ensuing scandal indicated a turf battle under way within the Vatican walls.
In addition, the Holy See is facing a structural deficit of a reported 70 million euros ($76 million), thanks in part to poor investments and decreasing donations from the faithful and dioceses around the world as a result of the sex abuse scandal.
The Vatican hasn't published a consolidated budget since 2015, and it remains without an auditor general after its first and only one left, allegedly after he started asking too many questions about the secretariat of state's assets.
Guerrero is currently in charge of the Jesuits' provincial houses and works, overseeing its three Rome universities, the Vatican observatory and magazine, as well other responsibilities covering 360 Jesuits from 69 provinces around the world. He is a key adviser to the Jesuit superior, the Rev. Arturo Sosa.
In a statement, Sosa said he had asked Francis to not promote Guerrero as a bishop, which would normally occur given his high-ranked job of prefect, but to keep him a simple priest so he can return to his life as a Jesuit after his term ends.
Guerrero said he was surprised and humbled by the appointment.
"I hope to contribute to the economic transparency of the Holy See and to help to use efficiently the goods and resources that are at the service of the important evangelizing mission of the church," he said in comments to Vatican News.
His appointment dashed speculation that a layperson, and specifically a laywoman, might be named to the post.
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