An increase in the crude reserves of Saudi Arabia and two other Gulf states boosted the Middle East's combined oil deposits by nearly 10 billion barrels this year. However, its gas wealth declined, according to international data.

From around 739.2 billion barrels at the start of 2007, the proven oil resources of the Middle East swelled to a record 748.2 billion barrels at the beginning of 2008, showed the figures by the Oil and Gas journal, Pennwell Corporation and the Energy Information Administration of the US Department of Energy. The increase was mainly due to a growth in the crude wealth of Saudi Arabia, Kuwait and Iran, while the UAE's proven oil reserves remained unchanged.

Saudi Arabia's recoverable oil deposits increased from around 262.3 billion barrels at the start of 2007 to 266.7 billion barrels at the start of 2008, maintaining its position as the world's oil superpower, which controls nearly a quarter of the total global proven crude reserves.

Iran's oil reserves rose from 136.2 billion to 138.4 billion barrels, the second largest in the world.

Iraq's reserves, the third largest, remained unchanged at around 115 billion barrels while Kuwait's oil wealth grew from nearly 101.5 billion to 104 billion barrels.

The UAE's oil resources, the fifth largest, remained unchanged at around 97.8 billion barrels.

The region's combined oil wealth has recorded a steady rise over the past two decades to peak at 748.2 billion barrels at the start of 2008 despite a sharp increase it its crude production. According to official figures, those five Gulf oil giants have pumped in excess of 70 billion barrels over the last 10 years.

Experts said the increase in deposits was a result of new discoveries in most regional producers and the introduction of sophisticated exploration and production techniques that boosted recovery rates at their oilfields.

At the beginning of 2008, the Middle East accounted for nearly 56 per cent of the world's total proven oil reserves of 1.33 trillion barrels, almost unchanged from last year's ratio despite an increase in global resources.

In contrast, the region's gas wealth recorded a decline for the first time in many years and the figures showed it was caused by a drop in the gas resources of Iran and Qatar, the second and third largest gas powers after Russia. From around 2,566 trillion cubic feet at the start of 2007, the Middle East's gas deposits declined to 2,548 trillion cubic feet at the start of this year.

Iran's reserves dropped from 974 trillion cubic feet to around 948 trillion cubic feet, while Qatar's fell from 910.5 trillion to 905.3 trillion cubic feet.

The report gave no reason for the decline but Iran and Qatar have largely boosted their gas production over the last 10 years.

At the start of this year, the Middle East's gas resources accounted for around 41 per cent of the world's total gas wealth of nearly 6,185 trillion cubic feet.

Other key gas producers in the Middle East included Saudi Arabia, whose reserves surged from 240 trillion to 253 trillion cubic feet. The UAE's gas wealth remained at around 214 trillion cubic feet while there was a slight drop in Iraq's resources from 112 trillion to 111.9 trillion cubic feet.

In Kuwait, recent discoveries boosted its gas potential to around 56 trillion from 55 trillion cubic feet in the same period.