* Pre-trial hearing begins into historical sexual offences
* Pell is highest ranking Vatican official to face suchcharges
* Australia's Pell not required to enter plea
* Cardinal Pell on leave of absence from Vatican (Recasts with opening by Pell's lawyer, request for supportperson; adds bullet points)
By Sonali Paul and Byron Kaye
MELBOURNE, March 5 (Reuters) - Lawyers for Vatican treasurerCardinal George Pell asked an Australian court on Monday toallow a support person to sit with him through a four-weekpre-trial hearing into charges of historical sexual offencesbecause of his age and ill health.
Pell, 76, a top adviser to Pope Francis, did not speak as hewas escorted by police through a group of media and protestersinto Melbourne Magistrates' Court for the start of the hearing.
Pell was summoned by Australian police last year and is themost senior Catholic official to face such charges. Details havenot been made public. lawyers have said at past administrative hearings thathe will plead not guilty to all charges. He is not required toenter a formal plea until a magistrate determines if prosecutorshave enough evidence for a case to be committed to a full trial.
The court was open to the public for less than half an hourfor legal arguments after it began.
It was later closed while Pell's accusers were questionedvia video link from a remote facility, which is normal underAustralian rules for cases involving sexual offences.
The hearing was expected to remain closed for up to twoweeks.
Prosecutor Mark Gibson asked the court to allow Pell'saccusers to have an assistant and a support dog next to them forcomfort. Both requests were granted.
Coop, a black Labrador, is used by courts in Victoria state,of which Melbourne is the capital, to ease the trauma for peopletestifying in sexual assault and family violence cases.
Pell's lawyer, Robert Richter, initially questioned thedefence request for Pell's accusers to have a support dog withthem while testifying.
"I always thought that dogs were for children and very oldpeople," Richter said.
Magistrate Belinda Wallington replied: "No, they're alsothere for vulnerable and traumatised people."
Richter also said it would only be fair to also allow hisclient to have a support person with him due to his "age andmedical condition", which Wallington said she would allow.
Richter did not say what type of assistant would accompany Pell and no other details were available.
Pell is on a leave of absence from his Vatican role as PopeFrancis' economy minister, which he started in 2014. The pontiffhas said he will not comment on the case until it is over.