Mumbai, April 29 -- Oil & Natural Gas Corpn Ltd is up for a third straight session today. The stock is quoting at Rs 305.25, up 1.31% on the day as on 12:49 IST on the NSE. The benchmark NIFTY is up around 1.36% on the day, quoting at 24321.3. The Sensex is at 77951.82, up 1.39%. Oil & Natural Gas Corpn Ltd has gained around 7.24% in last one month. Meanwhile, Nifty Energy index of which Oil & Natural Gas Corpn Ltd is a constituent, has gained around 18.49% in last one month and is currently quoting at 40990.7, up 0.74% on the day. The volume in the stock stood at 199.75 lakh shares today, compared to the daily average of 210.94 lakh shares in last one month. The benchmark May futures contract for the stock is quoting at Rs 306.2, up 1.34...