India's largest private sector firm Reliance Industries has reported a 28 per cent rise in quarterly net profit, boosted by earnings from refining crude and higher gas output.

The oil and petrochemical giant said net profit for the three months to September climbed to Rs49.23 billion ($1.03 billion) from Rs38.52 billion in the same period last year.

The figure, which was broadly in line with analysts' estimates, was the highest ever posted by Reliance during a three-month period.

'Improved refining margins and high operating rates at all our manufacturing facilities led to a record quarter,' said chairman Mukesh Ambani, India's richest man and the world's fourth wealthiest, according to Forbes magazine.

The conglomerate said sales rose 23 per cent to Rs574.79 billion ($13.5 billion).

The company, whose core businesses are petrochemicals and oil and gas, has recently been eyeing expansion in fast-expanding sectors like India's mushrooming telecommunications sector and retail.

'We are focused on identifying opportunities that leverage India's unique demographic and market potential,' Ambani said.

The company said gross refining margins - earnings from converting a barrel of crude oil into fuel - jumped to $7.90 a barrel during the quarter from $6 a year earlier.

Reliance said revenue from its oil and gas business leapt 47 per cent to Rs43 billion thanks to higher output from the Krishna Godavari basin off India's east coast.-Reuters