India is likely to sign a USD 78 billion deal to extend LNG imports from Qatar by another 20 years till 2048 at rates lower than current prices, sources said. Petronet LNG Ltd, India's biggest liquefied natural gas (LNG) importer, is likely to sign a deal with QatarEnergy to extend a 2004 deal to buy 7.5 million tonne a year of gas for producing electricity, making fertilizers and converting to CNG, on the sidelines of India Energy Week (IEW) here.