Russian conglomerate Sistema will invest up to $5 billion (about Rs 20,000 crore) in India's fast growing telecom sector in the next three years to create a world-class telecom network across the country.Sistema has finalised an agreement with Indian telecom services provider Shyam Telelink, the unlisted telecom services arm of the Shyam Telecom Group, to acquire 74% stake in the company.Senior management of Sistema would accompany Russian Prime Minister Victor A Zubkov on his 3-day visit to India beginning February 11.Shyam Telelink has got Letters of Intent for 22 circles on January 10 and is all set to get the spectrum to start rolling out mobile services network in association with Russian giant Sistema.Shyam is an existing service provider in Rajasthan and is offering mobile services under the Unified Access Services (UAS) license.Sistema has already committed $1 billion in investment for its plans in Shyam Telelink, said Alexender Goncharuk, president, Sistema."We will invest whatever it takes for a competitive world class all-India telecom network in the shortest possible time.The total investment in India would be in the range of $4-5 billion in the next three years," he added.The deal with Shyam Telelink has also marked Sistema's entry into the Indian telecom sector. Sistema is the largest mobile operator in Russia, seventh in the world, and has over 81 million wireless subscribers.Sistema's foundation businesses are telecommunications, high technology and real estate.