Inzamam-ul-Haq, Mohammad Yousuf and Imran Farhat were reported on Monday to have signed to play in the rebel Indian Cricket League (ICL).
In a move that could end their international careers with Pakistan, the trio were said to have been confirmed as part of the inaugural Twenty20 tournament later this year.
And Abdul Razzaq, who has quit Pakistan after being left out of their Twenty20 squad, is also reported to have joined the breakaway league, which is not sanctioned by the Indian cricket board (BCCI) - although he has so far denied any links.
Brian Lara is another big name already known to have signed a deal, along with former South African stars Lance Klusener and Nicky Boje.
More big names
Several other recently-retired players have been linked to the league, although many - including Glenn McGrath and Shane Warne - have denied signing up.
"We have delivered our promise to give you a star-studded line-up, and it is not over yet. Expect more big names to follow," ICL chairman and former India skipper Kapil Dev said.
The Twenty20 tournament will take place in October and November and the organisers, India's largest media firm, are looking for big names to raise the profile of the competition.
The boards of India, Pakistan and Sri Lanka have threatened to ban players if they join the league.