VATICAN CITY (Reuters) - Roman Catholic cardinals will start their conclave to elect a successor to Pope Benedict on the afternoon of Tuesday March 12, the Vatican said in a statement on Friday.

A total of 115 cardinals will take part in the elaborate ritual, which continues until one man receives a two-thirds majority. The vote follows Benedict's surprise abdication last month after a troubled, eight-year reign.

There is no clear favorite to take the helm of Church, which faces an array of problems, from sexual abuse scandals to internal strife at the heart of the Vatican administration.

(Writing by Crispian Balmer; editing by Barry Moody)