Defying a weak broader market,shares of state-run ONGC surged nearly 3 per cent on a new oil discovery in Gujarat,making its investors richer by over Rs 7,800 crore. Oil and Natural Gas Company (ONGC) settled at Rs 1,317.6,up 2.87 per cent,from previous close. The scrip witnessed a jump of 4.13 per cent to touch a high of Rs 1,333.90 during the day. ONGC was the top performer among the 30-bluechip firms trading on the BSE. The counter witnessed a similar trend on the National Stock Exchange and closed at Rs 1,315,up 1.95 per cent. "Oil discovery is the current trigger for ONGC and helped the stock outperform the broader market," Anand Rathi Securities Head of Research D D Sharma said. The company's market capitalisation swelled by Rs 7,849 crore to a total of Rs 2,81,828 crore. The broad gauge Sensex,however,finished the day at 17,998.41,down 1.25 per cent. On the volume front,over 19.5 lakh shares of the company were traded on the bourses. ONGC said that exploratory well Vadatal-1 in Nelp Block CB-ONN-2004/2 in the Tarapur area of the western onshore basin was found to be oil-bearing and the well indicated a potential of 278 barrels per day. Meanwhile,ONGC also said it will invest over Rs 372 crore to develop two marginal oil and gas fields off the West Coast-BHE and BH-35 area East of the Mumbai High South field. The fields will cumulatively produce 0.422 million tonnes of crude oil and 0.529 billion cubic metres of natural gas over a period of eight years,with peak production rates of 2,500 barrels per day of oil and 250,000 cubic metres of gas.