Oil and Natural Gas Corp has surpassed the Tatas in market capitalisation, with its market value of Rs 104,114.5 crore (Rs 1,041.14 billion) being more than that of all the 26 listed firms of the Tata Group.
Tata Group's market capitalisation, based on Thursday's closing price, was about Rs 97,666 crore (Rs 976.66 billion). This included Rs 48,215 crore (Rs 482.15 billion) market capitalisation of the recently listed Tata Consultancy Services.
According to industry analysts, ONGC's Thursday's closing price of Rs 730.15 on the Bombay Stock Exchange puts its market value at Rs 104,114.57 crore, making it the biggest firm in Indian history by market capitalisation.
Together with its subsidiary Mangalore Refinery and Petrochemicals Ltd, ONGC Group market capitalisation climbs to Rs 112,011.39 crore (Rs 1120.11 billion), making it the largest Group. At Rs 45.05 closing price, MRPL is valued at Rs 7896.82 crore (Rs 78.97 billion).
The Reliance Group is ranked third by market capitalisation, with a total value of Rs 87231.22 crore (Rs 872.31 billion) - Rs 68562.13 crore (Rs 685.62 billion) of Reliance Industries, Rs 11712.22 crore (Rs 117.12 billion) of Reliance Energy, Rs 1727.54 crore (Rs 17.27 billion) of Reliance Capital, Rs 108.41 crore (Rs 1.08 billion) of Reliance Industries Infrastructure Ltd and Rs 5120.89 crore (Rs 51.2 1 billion) of IPCL.
Analysts said the total market capitalisation of 26 listed firms of Tata Group had marginally breached the Rs 103,125 crore (Rs 1031.25 billion) mark last week, mostly on the strength of TCS but has since stayed below that magical figure.
TCS alone added Rs 47,232 crore (Rs 472.32 billion) to the Tata group's market capitalisation on the day of its listing, while the other 25 listed companies accounted for a m-cap of Rs 52,800 crore (Rs 528 billion).

