LOS ANGELES (Reuters) - Beyonce and Madonna have joined Fridays Hope for Haiti Now celebrity telethon for the earthquake-ravaged Caribbean nation, and actors George Clooney and Leonardo DiCaprio will each donate $1 million to the cause, their representatives said on Thursday. Beyonce will perform in London and Madonna will take the stage in New York in the evening benefit show being broadcast on all four leading U.S. networks, dozens of cable channels and internationally on Internet websites. DiCaprio is giving $1 million to the Clinton Bush Haiti Fund, which was started by former Presidents Bill Clinton and George W. Bush. Clooney, the Up in the Air star who organized the event, will officially make his $1 million donation during the telecast, his spokesman said. Stars who have already contributed to help Haiti include The Blind Side actress Sandra Bullock, who gave $1 million, Brad Pitt and Angelina Jolie, who donated $1 million, and model Gisele Bundchen, who gave $1.5 million. Pop star Shakira said on Thursday her Barefoot Foundation would build a school in Haiti. She will also perform in the telethon. Clooney, who will take part in the telethon from Los Angeles, told Entertainment Tonight he had been up for three days straight trying to put it together. Its first getting networks together, getting phone lines, phone banks, charitable organizations together and finding the way to get the money to them. Its a long process of making deals and trying to get things done, he said. Other notables taking part include Bill Clinton, U2 frontman Bono, singer Bruce Springsteen, rapper Jay-Z and actors Denzel Washington, Julia Roberts, Tom Hanks and Meryl Streep. MTV, the shows co-producer, has said Hope for Haiti Now: A Global Benefit for Earthquake Relief will be the most widely distributed telethon in history. Also on Friday, a Canadian telethon will feature entertainers from that country including Celine Dion, Sarah McLachlan, Nelly Furtado, Michael J. Fox and William Shatner, and retired hockey great Wayne Gretzky. Canada for Haiti will air on CBC, CTV and Global Television.