Asia is emerging as the most proactive region in trying to lure oil and gas companies, offering more exploration acreage than any other continent.

With galloping oil consumption at a third of total world demand, Asia is launching upstream auctions at a pace unmatched elsewhere.

The efforts, some of which have faltered, underscore some analysts' views that Asia has a large share of undiscovered oil to yield, but also highlights the increasingly closed attitudes of oil-rich nations, forcing firms to reconsider a region some gave up decades ago.

"Asia is fully on board with the strategy of attracting foreign risk investment capital to exploit its resources," said Michael Smith, chief executive of forecasting firm Energyfiles.

A poll shows Asian countries with 11 upstream rounds ongoing or in the pipeline for this year, more than double that for Africa, for instance.

Their strategy contrasts with that of top resource holders such as Saudi Arabia, whose oilfields are off limits to foreign investors, and with nations like Venezuela, which stripped major Western companies of control over huge projects this month.

"For a successful bid round, you first need to have prospective acreage which is potentially commercially viable given the terms and conditions of the countries' minerals and hydrocarbon management system," said Bob Fryklund, vice president industrial relations for consultancy IHS.

Firms will scrutinise the exploration programs and signature bonuses requested, as well as production splits in case of successful discoveries.

"Secondly, the procedure must be clear, transparent and understandable," Fryklund added.

Consultancy Wood Mackenzie forecasts overall production in the region will decline in the next 20 years from some eight million barrels per day - about 10 percent of the world total - to below six million bpd. But even the lower figure requires additional discoveries to replace dwindling fields.

The US Geological Survey estimated that there were about 20 billion barrels of undiscovered conventional liquids in the region at the start of 2006.

According to Wood Mackenzie, 28 percent of the region's oil production in 2025 will be from new fields.

Licensing rounds work well for underexplored nations that need to put themselves on the world oil map. East Timor organized a first round last year, awarding blocks to India's Reliance and Italy's Eni.

Even international oil companies have begun to take notice, despite an aversion to such open, public offers fueled by fears of overbidding.

But launching a round is neither a sure formula for success, nor a huge money-spinner in itself.

Papua New Guinea , which this year closed its first round in six years, failed to attract much interest.

Firms will look at oil potential, exploration maturity, availability of gas infrastructure and open acreage, as well as government attitude to investment.