Cairn Energy has sued India's flagship carrier Air India to enforce a $1.2 billion arbitration award that it won in a tax dispute against India, according to a US District Court filing reviewed by Reuters. The move ratchets up pressure on India's government to pay the sum of $1.2 billion-plus interest and costs that the British firm Cairn was awarded by an arbitration tribunal in December. The body ruled India breached an investment treaty with Britain and said New Delhi was liable to pay. Times Now's Megha reports Cairn Energy has taken an important step towards attempting to over the overseas assets of the Indian Government to enforce a 1.2$ billion arbitration award. Watch!