America's largest oil company, ExxonMobil, pleaded with politicians and regulators to hold off on new rules to curb drilling until the lessons of the Deepwater Horizon disaster have been fully understood.

Executives from the firm said they fear that the horrors of BP's Gulf of Mexico oil leak could prompt a rush of new legislation or regulation, causing long-term damage to the industry.

Speaking at the Asia Oil and Gas Conference in Malaysia, Andrew Swiger, a senior vice president of Exxon, said talk of imposing new restrictions on drilling was "premature".

The conference has been overshadowed by the environmental disaster unfolding off the US coast, and transfixed by BP's efforts to capture the oil that has been spilling into the ocean for almost seven weeks. "We caution anyone from trying to jump to conclusions and introducing regulations without fully understanding what happened," said Swiger.

"The industry has drilled thousands of wells in all manner of operating environments - whether it's deep-water or onshore - all around the world, without incident."

The Obama administration introduced a moratorium on new deep-water exploratory drilling in the US for six months, pending the findings and recommendations of a presidential commission investigating the causes of the explosion in April that sank the Deepwater Horizon rig leased by BP, killed 11 crew members and ripped open a hole in the seabed.

Exxon executives warned that "reactive" changes to deep-water drilling laws could damage long-term investment decisions, and that would have repercussions for energy policy, given what they described as the importance of deep-water wells in meeting energy demands.

"We need to guard against premature reactive changes to legislation that may not in the longer term be helpful but detrimental to the industry," Swiger said.

Mark Albers, another senior vice president of Exxon, told Reuters in Beijing that the impact of the moratorium on deep-water drilling in the Gulf would last much longer than the ban itself, and said that it takes time to understand the effect of new regulations and to bring the rigs back to work.

"It's important that in the next five years, deep-water will contribute 10 million barrels per day of oil (equivalent). That's equivalent to what Saudi Arabia is producing," he added.

Following the order to idle 33 deep-water rigs, Royal Dutch Shell, Exxon, Chevron and other firms have begun curbing Gulf of Mexico operations. Critics of the moratorium say it exacerbates the harm to a Gulf Coast economy which is already losing its fishing and tourism business to the spill.