Eton educated Welby, currently Bishop of Durham, becomes spiritual leader of the 80 million-strong Anglican Church replacing Rowan Williams who will step down after 10 years in the post next month.

But the appointment prompted mixed reaction around the world with issues relating to gay rights and same sex marriage likely to set the agenda in coming months.

The Anglican Archbishop of Sydney Peter Jensen said in a statement: ''We welcome the appointment of Bishop Welby to the ministry of Archbishop of Canterbury. It remains an important role though obviously the events of the last decade have diminished its significance in the worldwide Anglican Communion.

''Bishop Welby has our prayerful support. We look forward to him speaking with clarity from the word of God about the gospel and its impact on the issues confronting the Church in England and the West."

Those "events of the last decade" is a veiled reference to the concerns of Anglican bishops unhappy with the direction of the mainstream church.

Dr Jensen along with Anglican archbishops from Nigeria and Uganda raised those concerns four years ago at the Global Anglican Future Conference in Jerusalem.

It led to British media focusing on him as the new face of a stirring giant - the conservative evangelical Anglican movement.

Bishop Nicholas Okoh, the Primate of the Church of Nigeria, described the church as ''grievously disunited'' and reports on the BBC said the new Archbishop would have to tread very carefully on the issues of homosexual priests and same-sex marriage.

The appointment of Eton educated Welby was welcomed by the American Episcopal church.

It was its election of Gene Robinson - an openly gay man - as the Bishop of New Hampshire in 2003, that prompted the crisis in the Anglican Communion.

Bishop Robinson, who is to retire early, in 2013, citing the pressure of the backlash against him, which has included death threats, called Justin Welby an "immensely likeable and sensible man".

He added that it showed the Church of England was "thinking outside the box, which is exactly what is needed, and it would be a breath of fresh air for the Anglican Communion".

Welby said at a press conference that the question of gay marriage in his new global flock was a complicated issue "and not one to be handled today, off the cuff."

But he offered a definite olive branch to the gay community despite reaffirming his opposition to same-sex marriage. Welby pledged to re-examine his own thinking on homosexuality while speaking out against exclusion and homophobia.

"I know I need to listen very attentively to the LGBT communities and examine my own thinking prayerfully and carefully," he said.