Conclave to start April 18, pope's will to be read Thursday: Vatican

Vatican City - Cardinals of the Roman Catholic Church will begin a conclave to elect a successor to Pope John Paul II on April 18 and his testament will be read out on Thursday, the Vatican announced.

Eligible cardinals -- those under age 80 -- will begin the closed-door discussions in the afternoon of April 18, Vatican spokesman Joaquin Navarro-Valls told a news conference on Wednesday.

"At 10:00 am (0800 GMT) a mass will be held, and they will start their conclave in the early afternoon," the spokesman said.

Navarro-Valls also announced that John Paul II's testament to the Roman Catholic Church has been opened and read by the Vatican's cardinals but will not be published until Thursday.

"It is too serious to give a will to any translator," said Vatican spokesman Joaquin Navarro-Valls. "The testament will be published Thursday in Polish, his native language, and in Italian."

John Paul II wrote the 15-page document in phases over the 26 years of his his pontificate, the spokesman said.

"His will of some 15 pages was written at various stages of his papacy, sometimes only a few lines, at times half a page. The first part was written in 1979, the year after the beginning of his papacy," he said.

Navarro-Valls also said the testament did not reveal the name of a cardinal the late pope nominated two years ago but whose identity he kept secret.

The cardinal is referred to in Church parlance as "in pectore," or in the heart.

Of the 117 cardinals eligible to vote, 116 are expected to take part in the election of the next pope, with Cardinal Jaime Sin of Manila unable to attend because of illness.

Meeting in the Vatican's Sistine Chapel, they will cast ballots four times a day until they reach a two-thirds majority to elect the 264th successor to Saint Peter.