Royal Dutch Shell's disclosure of its carbon emissions lags behind its closest rivals and falls well short of best practice, a study by an industry consultant has said.

PFC Energy said Shell, which has sought to assert its green credentials, was rated bottom out of six multi-national oil companies surveyed on the level of detail, frequency and coherency of their emissions disclosures.

For nearly two years the Opec oil cartel has watched oil prices rise with a mixture of delight and foreboding.

Record global food prices will be on the agenda of the Group of Eight heads of state summit in July for the first time in almost 30 years, amid mounting concerns about the social, political and economic impact of the food crisis. The International Monetary Fund on Monday gave its starkest warning about the impact of rising commodities, saying food and oil prices "risk becoming a destabilising force in the global economy'. Yasuo Fukuda, Japan's prime minister, said in a letter to his G8 colleagues that soaring food prices were posing "imminent and serious' global challenges.

Saudi Arabia, the world's biggest oil producer, has put on hold any plans to further increase long-term production capacity from its vast oil fields, its most powerful policymakers have said. In a series of statements, including one by the king himself, the kingdom has warned consumers it does not believe there is a need for further expansion, an assumption disputed by the world's biggest developed countries.

Five years ago Russia's rapidly growing oil exports were seen as the cure for the US and Europe's addiction to Middle East oil, international oil companies' most exciting potential source of revenue and the only thing that could quench China's insatiable new thirst.

The Organisation of the Petroleum Exporting Countries has quietly begun to reduce its oil production despite calls from the US and Europe for the group to pump more so that prices fall. Output from the core countries of the 13-member cartel last month fell to 27.3m barrels a day, down from the 27.6m b/d they produced in February and 27.8m b/d in January, the International Energy Agency, the western countries' watchdog, said yesterday in its monthly report. Production from Saudi Arabia, Opec's largest member, dropped marginally from January and was the same as February at 9.2m b/d.

China yesterday signed two multibillion-dollar long-term deals to buy liquefied natural gas from Qatar, marking a milestone in Asia's evolution as the hottest market for the fuel. PetroChina struck a deal to buy 3m tonnes of LNG a year over 25 years from 2011 with Qatar and its partner, Royal Dutch Shell. Analysts said the deal could could be worth as much as $60bn. CNOOC, China's primary LNG importer, also signed a framework supply agreement. Al-though it is yet to be formalised in a binding contract, it is for 2m tonnes a year from 2009.