The partners have now brought in Star India, which broadcasts international cricket in India, as a joint investor in a deal, giving the media subsidiary of Mr Murdoch's 21st Century Fox about a third of the ISL and sponsorship rights for the tournament.
According to Indian media reports, the Star India investment is worth between Rs 15 billion and Rs 20 billion over 10 years.
Nita Ambani, the wife of India's richest man and chair of IMG-Reliance, said in a statement issued by IMG: "Football, with its largely untapped potential in the country, has the opportunity to grow to an unrivalled commercial success quite unlike any other sport. We hope the growing football footprint will pave the way for the nation's sporting renaissance."
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The tournament has been given a start date of January 18 and will run until March. Each team will have a marquee player as well as other players from abroad and players from India.
The ISL so far has options on signing up six international players, all of whom have finished their careers, and three international managers. Games will be played over 10 weeks in football and cricket stadiums, and the tournament will last 61 matches.
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Unlike cricket's IPL, the Indian Super League is largely a top-down approach to growing football in the country.
Jeff Slack of IMG said: "India just doesn't have a grass-roots programme. If we just did that, it's not going to inspire many kids."
The lack of football stadiums was Indian football's "Achilles heel", said Mr Slack. But India's football infrastructure could be boosted if the country wins its attempt to stage the under-17 world cup.