* Robinson says only a council can make effective change
* New pope has raised hopes among Catholics for reform
* Online petition a novel way to address the Vatican (Corrects "new organisation" to "meeting" in third paragraph)
By Tom Heneghan, Religion Editor
June 4 (Reuters) - A retired Australian bishop urged Roman Catholics around the world on Tuesday to sign an online petition to Pope Francis to call a new global council to take effective measures to end the sexual abuse of children in the Church.
Bishop Geoffrey Robinson, a former auxiliary bishop of Sydney who coordinated the Australian church's response to the sexual abuse crisis, said only a council of the world's bishops would have the power to make the changes needed.
The meeting would be akin to the 1962-1965 Second Vatican Council, Robinson told a news conference in Sydney, referring to the historic body that transformed the Catholic Church with modernising reforms.
But this council would focus only on solving the abuse issue, he added.
Robinson said Francis had "given out a lot of good signals" since his surprise election in March.
The Argentinian-born pontiff, 76, has raised hopes for change among Catholics worldwide by ignoring Vatican protocol and openly addressing controversial issues, but it was not clear how he would react to an innovation like an online petition.
"The petition is not to challenge him, it's to help him, to indicate that the people are with him in really looking at these factors and changing whatever needs to be changed," Robinson said at the conference broadcast by Australia's ABC television.
FOR CHRIST'S SAKE
The scandal of priests molesting minors has haunted the Catholic Church around the world for over two decades, sapping its moral authority, shaming bishops and priests involved in abuse or its cover-up and costing huge sums in damage payments.
It overshadowed the eight-year papacy of retired Pope Benedict, even though he publicly apologised for the abuse several times and met victims on many of his trips.
Robinson spoke at the launch of his new book "For Christ's Sake: End Sexual Abuse in the Catholic Church ... for Good". His petition, which has been online for several weeks, reached 15,000 signatures on Monday.
Australia's senior Catholic prelate, Sydney Cardinal George Pell, apologised to abuse victims at a parliamentary hearing last week and promised to work with a major official inquiry due to look into child sex abuse in Australian institutions.
Robinson's petition, online at www.change.org/forchristssake, says signatories are "sickened by the continuing stories of sexual abuse within our Church and ... appalled by the accounts of an unchristian response to those who have suffered."
Lay Catholics should have a major voice at the Council, it said, and discuss problems such as Church teaching on sexual morality, the requirement of priestly celibacy, the lack of women's influence in Church decision-making, a culture of secrecy and a Vatican emphasis on protecting papal authority.
The Second Vatican Council launched modernising reforms such as using local languages in the liturgy, opening relations with other faiths, especially Judaism, and promoting more dialogue between the Vatican and Catholic bishops around the world. (Reporting By Tom Heneghan; Editing by Andrew Heavens)