After five years and more than $15 billion of investments, Mukesh Ambani said his Reliance Industries could be ready to begin 4G phone services in December.

Reliance, India's second-largest company by market value and led by India's richest man, derives most of its revenue from its sprawling energy empire, but has over the past few years expanded into areas such as media, retail and telecoms to counter a slowdown in the energy business.

It re-entered the telecoms sector in 2010 but its efforts to launch services across India have been hit by infrastructure and technology delays.

Analysts and investors have fretted over the costly bet -- more than $15 billion for the digital business to date, including the Jio 4G venture -- by a company that has limited experience in businesses that serve consumers directly.

"All the key components of the Jio broadband network are now operational," Ambani, who is ranked 44 in the Forbes global rich list, told shareholders in an hour-long speech on Friday.

"Over the next few months, we will initiate an extensive beta launch ... This beta program will be upgraded into commercial operations around December of this year," he said.

Ambani, whose father founded Reliance, is rarely seen in public. The group's annual general meeting is attended by hundreds of small shareholders, and usually features songs and poetry in the family's honour.

Cash-rich Reliance's entry into the crowded telecoms sector is a potential threat for established players such as Bharti Airtel Ltd BRTI.NS and Vodafone's local unit.

Seeking to make its 4G services available to more Indian consumers, Ambani said the company had worked with manufacturers to produce cut-price phones. He expected 4G LTE smartphones priced below 4,000 rupees ($63) would be available in the Indian market by December.

Reuters reported last month that Reliance was in talks with Chinese phonemakers such as Gionee, Huawei and Xiaomi.

Reliance will offer its own 4G services for as little as 300 rupees a month, Ambani said.

Reliance has a WhatsApp-like smartphone messaging application called Jio Chat and is working on cloud storage, music streaming, news and mobile payment applications. Jio also plans to enter into broadcast television distribution.

Ambani said Reliance's retail business, which includes groceries, apparel and electronics, will expand to more than 900 cities by next year from 200 cities now.

The retail business, India's largest, will also roll out e-commerce initiatives by the end of the year. The business should grow at an annual rate of 30 to 50 percent, Ambani said.-Reuters