* Defence, prosecutor agree to seek two separate trials
* Prosecutor estimates each trial to take around 5 weeks
* No date yet set for full trial
* Pell on leave of absence from role as Vatican economy minister (Updates throughout with comments from judge and Pell's lawyer, adds background on case)
By Sonali Paul
MELBOURNE, May 2 (Reuters) - The trial of Vatican Treasurer George Pell, who has pleaded not guilty to charges of historical sexual offences, is expected to last 10 weeks, an Australian court heard on Wednesday, with his defence lawyer seeking speedy action.
The County Court of Victoria state will hold a second hearing on May 16 to plan how to proceed, with the prosecution and defence agreeing to press for two separate trials, each estimated to take about five weeks.
Pell, 76, is the highest ranking Catholic worldwide to face a criminal trial on sex offences. Details of the charges have not been made public.
The Victorian Magistrates' Court ordered on Tuesday that Pell face trial on historical sexual offences involving multiple accusers following a month-long pre-trial hearing. Pell formally entered a not guilty plea. trial dates have been set yet.
Pell's lawyer, Robert Richter, urged the County Court to move forward as quickly as possible on the charges, which involve offences alleged to have occurred 20 years apart at a public swimming pool and a church.
"We would like an expedited trial for various reasons - number one, my client is 76 years old," Richter told the court.
Richter also said a "critical witness" for the case involving alleged offences at the church was 80 and in ill health.
"We would suggest the indictment for that one could proceed separately and quickly," Richter said.
Prosecutor Mark Gibson initially estimated it would take three months to prepare for trial but Judge Susan Pullen said that seemed excessive.
"You've got to move on with this," Pullen told the prosecutor.
Pell is on a leave of absence from his role as economy minister to Pope Francis, who has said he would not comment on the case until it was over.
The Vatican said in a statement it had "taken note" of the court's decision to proceed to a full trial. The leave of absence the pope granted Pell last year so that he can defend himself against the charges "is still in place", it said. defence team raised questions during the pre-trial hearing about police procedure, the reliability of witnesses' memories and their psychological condition.
Prosecutor Mark Gibson had said none of the complainants had resiled from their allegations against Pell under cross-examination, while Victoria Police Detective Sergeant Chris Reed denied Richter's suggestions of serious flaws in the police investigation.