The total size of buyback is Rs 4022 crore, the company said. The company has fixed 4 January 2019 as the record date for the buyback. The announcement was made during trading hours today, 20 December 2018.

Meanwhile, the S&P BSE Sensex was down 51.77 points, or 0.14% to 36,432.56.

On the BSE, 8.56 lakh shares were traded in the counter so far compared with average daily volumes of 7.32 lakh shares in the past two weeks. The stock had hit a high of Rs 150.80 and a low of Rs 147.50 so far during the day. The stock hit a 52-week high of Rs 212.90 on 25 January 2018. The stock hit a 52-week low of Rs 134.75 on 11 December 2018.

ONGC's net profit rose 61.1% to Rs 8264.61 crore on 47.6% increase in net sales to Rs 27989.17 crore in Q2 September 2018 over Q2 September 2017.

ONGC is the largest crude oil and natural gas company in India, contributing around 70% to Indian domestic production.