MUMBAI/NEW DELHI - Disney, Sony and India's Reliance will vie on Sunday for media rights to Indian Premier League (IPL), the world's richest cricket league, expected to fetch up to $6 billion.

The IPL, counting top Indian industrialists and Bollywood stars such as Shah Rukh Khan among its franchise owners, is often seen as a surefire ticket to high TV ratings and growth in India's booming online streaming space.

But while the digital and television rights for 2023 to 2027 are expected to more than double the 163.48 billion rupees ($2.09 billion) that Star India, now owned by Walt Disney Co, paid in 2017 for the rights through this year, some observers say caution may be setting in.

"There is also a global shift toward saner valuations, where investor expectations have shifted from ‘growth-at-any-cost’ to ‘growth-with-profitability’," said Mihir Shah, vice president of consultants Media Partners Asia.

India's cricket board (BCCI) will begin the online bidding for the rights from 0530 GMT on Sunday, treasurer Arun Singh Dhumal told Reuters. Results are expected later on Sunday.

"IPL is the hottest property in cricket and it has just been expanded to a 10-team tournament, which means there will be more matches," Dhumal said. "All of it should reflect in the value of the new media rights, which we expect to be significantly higher than our previous deal."

Gujarat Titans, owned by European buyout firm CVC, won the 15th edition of the league, beating Rajasthan Royals in the May 29 final in front of more than 100,000 fans in Ahmedabad.

The glitzy T20 league draws the planet's best cricket talents for two months of fast-paced matches played to packed stadiums with cheerleaders and live music.

But in a sign of potential limits to the boom, Amazon.com Inc pulled out of the bidding process on Friday, saying it did not think it was viable growth option for the company in India.

Reliance Industries Ltd will bid through its broadcasting joint venture, Viacom 18. Sony Corp's India unit and local broadcaster Zee Entertainment are in merger talks but will bid separately.

"Viacom 18 will probably be the most aggressive of the three main players, because this builds into their long-term plans, including upping valuation for a possible Jio IPO in the future," a source with knowledge of the company's plans told Reuters.

The e-bidding process will be for broadcast rights, digital rights, a bespoke package that includes rights for high-value matches as well as rights to broadcast in foreign territories.

Last time, Star India won a consolidated bid that gave it broadcasting rights on both television and digital platforms.

"At renewal value of $5 to $6 billion or more, the rights would require the winner to attain significant scale in the $20 billion competitive streaming and TV industry," Shah said.

(Reporting by Shilpa Jamkhandikar and Amlan Chakraborty; Editing by William Mallard)