* Tycoon Ambani plans 4G data at 50 rupees per gigabyte
* No date yet for commercial launch
* Test customers to get services free until Dec 31
* Shares in rivals Bharti Airtel, Idea Cellular slump (Adds further details)
By Promit Mukherjee
MUMBAI, Sept 1 (Reuters) - India's Reliance Industries unveiled its new telecom network on Thursday, toutingfree calls and rock-bottom data prices that sent shares ofestablished telecom players into a nosedive on fears of anall-out price war.
Reliance's Chairman Mukesh Ambani, India's richest man, toldshareholders at the energy giant's annual shareholder meet thatservices on the new network, dubbed Jio, would be available forfree until Dec. 31 as it continues network tests. He did not saywhen the services would be launched commercially.
Reliance, one of India's biggest business houses which getsmost of its revenue from its sprawling oil and gas business, hasin the recent years expanded into more consumer-facing marketssuch as retail and telecom as growth in its core business slows.
The company, which secured telecom airwaves in 2010, has sofar invested more than $20 billion on building a nationwidenetwork, and has pledged to offer affordable services toprice-conscious Indian customers.
Ambani, who was interrupted by repeated rounds of applauseas he took shareholders through Jio's ambitious rollout plans,free countrywide roaming offering and more, vowed to "transformIndia from a high-priced data market to one with the lowest datarates anywhere in the world."
Jio could make Reliance a big provider of telecoms andinternet services across India - a nation of one billion mobilephone subscribers - and is a key plank of Ambani's futurestrategy even though the business is unlikely to addsignificantly to consolidated profit any time soon.
Jio will effectively price one gigabyte of data at about 50rupees for some users, about one-fifth of what rivals charge,Ambani said. Data charges will fall even further for heavierusers, he said.
Ambani set a target of 100 million customers for RelianceJio "in the shortest possible time", without specifying.
Shares in India's No. 1 wireless carrier Bharti Airtel Ltd dropped 6.3 percent on Thursday, while smaller rivalIdea Cellular fell 10.5 percent, on fears that Jio'saggressive rates will trigger a price war in the sector.
The incumbents have already started lowering data pricesahead of Jio's entry.
Still, a telecom analyst, who declined to be named, said Jiowould face challenges in luring low-spending phone users to itsnetwork.
Jio's cheapest plan starts at 149 rupees and offers just 0.3gigabytes of data and the company's next plan up costs 499rupees, while a majority of India's phone users who still havebasic phones spend less than 200 rupees a month ontelecommunications services.
"It is definitely aggressive and will hurt the incumbents,"he said. "But it's not like it's going to push everyone else outof the market."
($1 = 66.9475 Indian rupees) (Writing by Devidutta Tripathy; Additional reporting by SwatiBhat and Rahul Bhatia; Editing by Kenneth Maxwell and MarkPotter)