Meanwhile, the company's revenue for the period under review saw a 13 per cent increase to Rs 59,891.27 crore compared to Rs 51,599.52 crore during the April to June quarter of 2016-17.

"The drop in net profit was mainly due to a higher inventory loss of Rs 1,595 crore, against an inventory gain of Rs 1,935 crore during the first quarter of the previous financial year," said M K Surana, chairman and managing director of HPCL. The Indian basket crude price dropped by $4.56 per barrel during April to June quarter of 2017 as against an increase of $10.89 a barrel last year. The inventory loss in marketing for the quarter stood at Rs 960 crore, while that of refinery stood at Rs 636 crore.

The gross refining margin of the company stood at $5.86 a barrel as compared to $6.83 a barrel during the first quarter of 2016-17. After adjusting inventory losses, core GRM for the quarter stood at $8.81 per barrel.

As on June 30, the company's debt stood at Rs 12,200 crore, down from Rs 21,250 crore on March 31.

The company has achieved a combined throughput of 4.49 million metric tonnes with a capacity utilisation of 114 per cent as against a throughput of 4.48 MT during the same period last financial year.

HPCL also achieved a domestic market sales of 9.20 MT, which is the highest sales volume by the company in a quarter.

When asked about the upcoming acquisition of 51.1 per cent government stake in HPCL by ONGC, Surana said the deal would bring synergy for HPCL in terms of petrochemical business.

"We are yet to get a first hand information from the government in this regard and that we have already informed the stock exchange. However, the process has already started as valuation advisors are working on it," he added.

He added that the company is not going slow on any of its investment and expansion plans. "For the financial year 2017-18, we are investing about Rs 7,100 crore in various projects including refineries, marketing and pipelines," he added.