MANCHESTER, New Hampshire — A New Hampshire priest who was the former leader of one of the nation's top clergy treatment centers was sentenced Wednesday to up to 20 years in prison for stealing at least $104,000 from a hospital, a dead priest's estate and the state's Roman Catholic bishop.

Monsignor Edward Arsenault held several senior positions in the New Hampshire diocese from 1999 to 2009, when he became president and CEO of Saint Luke Institute in Maryland. He resigned in May after allegations arose involving an inappropriate adult relationship and misuse of church funds.

Arsenault pleaded guilty Wednesday to three felony theft charges, which included a theft of at least $104,000 from Catholic Medical Center in Manchester, where he had done some consulting. When his initial plea was announced in February, prosecutors would say only that he committed a felony in each case by stealing more than $1,500 from the hospital, the estate of a Manchester priest who died in 2010 and the bishop.

The plea agreement calls for Arsenault to serve 4 to 20 years in prison. He will go back to a judge after serving the minimum to determine if the sentence can be reduced.

Prosecutors have said Arsenault stole from the bishop between 2005 and 2013, from the hospital between 2009 and 2010 and from the estate of Monsignor John Molan between 2010 and 2012.

The investigation did not involve Saint Luke Institute, a prominent education and counseling center based in Silver Spring, Maryland, with sites in other parts of the U.S. and in Britain. The center treats priests with a range of mental illnesses and has played a key role in addressing the problem of sexually abusive clergy.

In New Hampshire, Arsenault had been former Bishop John McCormack's top lieutenant, handling the clergy sexual abuse crisis and was responsible for the church's new child protection policies.