"I am one of the strongest supporters of separating oil and gas (pricing) given the rising cost of extracting gas and the high investments needed for gas developments..." Qatar's Abdullah bin Hamad al-Attiyah said in a recent interview.

"This is rejected by some Opec producers and the link between these two products still exists. I believe a separation is inevitable because gas has an environmental advantage..."

Attiyah, whose country sits on the world's third biggest natural gas reserves, is the first minister to call for a change in the system whereby gas is indexed to crude oil in complex formulae that vary according to delivery point.

"The rule is that when oil prices are high, sellers seek asteep association with oil. When prices are low, they seek to separate from oil," says James Ball of GasStrategies.

With oil prices still hovering near 22-year lows despite arecent rally after oil producers agreed a new round of output cuts, other major gas producers like Algeria and Russia have hinted that they too would like to free gas from oil.

But analysts say this is easier said than done, given that the life of gas contracts runs at 20-25 years and the fact many markets are still controlled by monopolies.

Officials from Russian Gazprom, the world's biggest gas company, were quoted recently as telling a gas meeting in Algiers that they were considering switching sales to Asia where prices are higher.

Analysts say Gazprom cannot afford to abandon a main export market and allow northern European producers a free hand. The situation was acute last year in Europe, where prices are indexed to crude oil in a market that is only now being liberalised. Europe is Algeria's biggest gas market while Gazprom is the biggest exporter of gas through a network of existing pipelines to eastern and centralEurope.

When crude oil falls to $10 a barrel, as it did late last year, then gas prices in Europe fall to their minimum price of $1.3-$1.5 per million btu (British thermal unit).

Some analysts say gas producers are likely to find little sympathy among customers who are locked into long-term take-or-pay contracts concluded when oil prices were far higher and are unable to renegotiate them.

Ali Aissaoui, senior research fellow at the Oxford Institute of Energy Studies, wrote recently that gas could not afford to price itself out of the market.

"You can only sell gas when it can compete with oil. It must follow oil down or you can't sell it. It must follow it up because you can always sell in competition with oil," Ball said.

Northern European producers, for example Norway's Norsk Hydro and state-run Statoil say they have no plans to change the way their gas is sold.

Only in the free markets of the United States and in Britain are gas prices been determined by supply and demand. In the mature USmarket, gas trades at a premium to crude oil.

The entry of power companies into the gas business has tipped the balance against gas 87 producers/exporters, particularly Algeria, which unlike Russia, does not have a downstream presence in Europe.

In Europe, North Sea gas producers are competing with each other and with Gazprom while in the southern Mediterranean market, Nigeria has secured sales deals for its new LNG plant to Italy, Spain, Portugal and Turkey.

Analysts believe Gazprom and other traditional suppliers of natural gas to Europe would find it difficult to switch tactics and adopt a new pricing or marketing policy overnight.

Gazprom said recently that it and Dutch gas company Gas unieplanned to sell gas jointly to Britain once the Yamal-Poland pipeline is completed. This would provide a direct link for Russian gas to Britain through Germany, Belgium and the Anglo-Belgian Interconnector pipeline.

The pipeline has changed the face of gas trading in Europe, with gas moving both ways dependingon price movements. A small amount of spot trading has also started in Belgium's Zeebrugge.

But analysts say delinking cannot happen unless there is direct gas to gas competition in liberalised markets that would allow producers and consumers to hedge against price risk.

"As market developments unfold and pressure on prices increases, producers/exporters will have to find fresh ways to differentiate themselves, take advantage of new opportunities downstream and add value to their gas business," Aissaoui said.