"In the coming year we would be working on bio-fuels and solar strategy," said Ambani, who will soon oversee the world's biggest refining complex.

Reliance Petroleum, a subsidiary in which U.S major Chevron Corp has a 5 percent stake, is setting up a 580,000 barrel per day (bpd) refinery, at Reliance's Jamnagar complex in the western Indian state of Gujarat.

Together with Reliance Industries' adjacent 660,000 bpd refinery, the new unit will make the Jamnagar complex the world's biggest, with a capacity of 1.2 million bpd.

A source had told Reuters in April Reliance would begin testing its new refinery in July and commission it in September. Ambani said on Thursday it would open in three to six months.

Ambani also said Reliance Industries, India's highest valued listed firm, should start producing gas from its Krishna-Godavari (KG) basin fields off India's east coast before the end of 2008.

Shares in Reliance, which have a market value of US$77 billion, closed up 1 percent at 2,281.75 rupees, its strongest finish since June 4, in a Mumbai market that rose 0.4 percent.

POLYESTER KING

Ambani said Reliance's polyester capacity rose by a quarter to 2.5 million tonnes a year after it bought the assets of Malaysian polyester maker Hualon Corp last year.

The company would focus on speciality polyester, looking for opportunities in automotive, medical and construction fields.

"Reliance envisages consolidating further its global leadership in polyester by pursuing greenfield investment and acquisitions in the entire value chain," Ambani said.

He said Reliance would commission annual capacity of 0.9 million tonnes of polypropylene at Jamnagar later this year, making it the third-largest polypropylene maker in the world.

"The petrochemicals business would first be driven by new capacities that Reliance would be bringing on stream in the context of buoyancy in demand," Ambani said

Reliance is spending about US$9 billion on development and production from the Dhirubhai 1 and 3 fields, named after Ambani's late father, and is set to pump up to 80 million cubic metres of gas per day (mmscmd) later this year.

Reliance Industries has made a total of 41 oil and gas discoveries to date, Ambani said. The finds include an oil discovery with an estimated peak production of 40,000 barrels per day in the KG basin.

India, Asia's third largest oil consumer, is encouraging use of natural gas to control its oil import bill and inflation, but there is not enough supply to satisfy rising demand.

Gas demand in India runs at around 179 mmscmd, but availability is only around 95 mmscmd. Production is expected to rise to more than 190 mmscmd after the new gas fields, including Reliance's, come on stream.

Goldman Sachs estimates the share of natural gas in India's coal-dominated energy basket will be double to 18 percent by 2015 and stabilise at 20 percent by 2025. (Additional reporting by Manoj Dharra; Editing by John Mair/Elaine Hardcastle)