Pakistan trio Inzamam-ul-Haq, Mohammad Yousuf and Abdul Razzaq head a list of stars joining the rebel Indian league.
Inzamam scored 8,813 Test and 11,739 ODI runs in 16 years
Former South Africa players, Lance Klusener and Nicky Boje, Indian batsman Dinesh Mongia and Pakistan opener Imran Farhat have have also signed contracts.
Pakistan and India say they will ban participants from their national teams.
Inzamam, 37, quit the Test captaincy and one-day internationals after the World Cup but had been expected to continue playing as a batsman.
He and his countrymen join former West Indies captain Brian Lara in becoming high-profile participants in the rebel league, which will initially feature Twenty20 matches played over two months over the next three years.
Another Pakistan player, batsman Younis Khan, rejected an offer, telling Bigstarcricket.com: "I still feel that I have another four or five years of international cricket in me and I don't want to jeopardise that.
"I am not anti-ICL, though. Maybe in the future I will take up their offer. They offered me a lot of money to play and I was very grateful."
Australian duo Glenn McGrath and Shane Warne have also been linked with this year's competition, which begins in October. The ICL paraded 44 Indian first-class cricketers at Monday's media conference.
Our focus is to entertain people who sometimes only see Test cricket
Officials refused to divulge the sums being paid to players, but one source said they were "more than enough to make the players happy."
Media reports said some domestic cricketers, who earned a maximum of 500,000 rupees [£6,000] from the Indian cricket board (BCCI) during a season, were reportedly being given nine million rupees [£110,000] by the ICL for three years.
"Our focus is to entertain the people of our country who sometimes only see Test cricket, they don't see any other cricket," ICL chairman and former India captain Kapil Dev said.
"I think these boys have the ability and the talent."
Meanwhile the BCCI says it will increase fees for domestic cricketers by 20%, but insists the threat of the ICL is not the reason for the rise.
BBC sports editor Mihir Bose said the breakaway league was "gathering momentum".
"They'll get ex-players or players right at the end of their career," he told BBC World.
"But unless they get the really big players who are playing now, they're not going to threaten the existing arrangement on the sub continent."
He added: "What's interesting is neither board has actually banned players. They're basically saying 'If you join you're leaving us, we're not going to select you'. So they haven't gone for the ultimate sanction."