The appeal comes five years before the customary bishop's retirement age of 75, and three weeks after a Herald interview in which he said the church was "compromised" by silence about "sexual abuse, the elephant in the room".

In a message to priests last week, Bishop Malone said he wrote to the Pope on August 20 and asked him to consider appointing a Coadjutor Bishop, or successor, to the diocese.

"The past 15 years have been difficult and it would be good to share the responsibilities of the diocese with a Coadjutor Bishop," he told priests.

"I did this in light of my 70th birthday in October and with the knowledge that the process of appointing a new bishop is often a lengthy one. From an initial request to an appointment could take many months, if not years.

"I would like to think that fresh and creative leadership would shape the future direction and allow for smooth forward planning for the Catholic Church in the diocese."

Bishop Malone denied that his request was linked to the Herald article, in which he mused that his criticism of fellow bishops, including a joking reference to them as "pussycats", might bring about his retirement "10 days from now".

He said he had not spoken with the two most senior bishops in Australia, former Maitland-Newcastle priest and Adelaide Archbishop Philip Wilson, and Sydney's Cardinal George Pell, about issues raised in the article, which include his belief that the silence of the bishops after the papal apology during World Youth Day in Sydney last year could be called a denial of responsibility.

He had raised the issue at both bishops' conferences held since World Youth Day, and would most likely raise it again at the next conference in November, despite both previous attempts failing to prompt discussion.

But he did not support calls for the Catholic Church to hold an inquiry into the extent of past sexual abuse in the church, and church responses, similar to an investigation held by the Anglican Church in Australia, which released a report in June.

In his message to priests Bishop Malone said the Coadjutor Bishop "automatically succeeds the current bishop of a diocese upon the latter's retirement or death".

The former East Gosford priest's appointment as Coadjutor Bishop to the then Maitland-Newcastle Bishop Leo Clarke in 1994 was a surprise.

But a letter obtained by the Herald this week shows the shadow of sexual abuse by priests has hung over Bishop Malone's tenure from his first days in the diocese.

In October 1995, as police charged Maitland-Newcastle diocese priest Vince Ryan with child sex offences that led to his jailing, and compensation payouts of $6 million to his victims, Bishop Malone was ending the priesthood of one of the Hunter's most notorious pedophile priests, Denis McAlinden.

"I regret that one of my first duties as Bishop is to continue Canonical procedures against you," Bishop Malone wrote to McAlinden in the same week that Ryan was charged.

Last month he admitted feeling "battered" by the most recent charges against priests.