The Vatican department that oversees relations with Islam is preparing guidelines for Catholic dialogue with non-Christian religions, its head said on Wednesday.

Cardinal Jean-Louis Tauran told Vatican Radio that work on the document was starting "after many years of hesitation" and would offer guidelines for priests as well as ordinary followers.

Tauran, a Frenchman, is head of the Pontifical Council for Inter-Religious Dialogue, which oversees Catholic relations with all non-Christian religions except Judaism.

The Vatican's relations with Islam have been particularly thorny in recent years.

In March, the Vatican and Muslim leaders agreed to establish a permanent official dialogue, known as "The Catholic-Muslim Forum", to improve often difficult relations and heal wounds still open from a controversial papal speech in 2006.

Catholic-Muslim relations nosedived that year after Pope Benedict delivered a lecture in Regensburg, Germany, that was taken by Muslims to imply that Islam was violent and irrational.

Muslims around the world protested and the pope sought to make amends when he visited Turkey's Blue Mosque and prayed towards Mecca with its Imam.

Tauran did not say when the new document would be completed.