Exxon Mobil, Chevron, ConocoPhillips and Royal Dutch Shell announced they would each contribute 250 million dollars to create a non-profit group, the Marine Well Containment Company, to contain oil.

BP was not included in the plans.

The new venture would design, build and operate a flexible system that, in case of a deepsea oil gusher, could mobilize within 24 hours to siphon and contain 100,000 barrels of oil per day in depths of up to 10,000 feet (3,000 metres), the companies said.

Its main goal would be to prevent a spill as large as the one unleashed by BPs busted Macondo well that sits 5,000 feet (1,500 metres) below the surface and was estimated to have spewed up to 60,000 barrels of oil a day until it was capped last week.

"This new system significantly enhances the industrys ability to effectively respond to any unforeseen incidents," Chevron chairman and chief executive John Watson said in a statement.

The companies said the system, which closely matches the one BP has in place after its leased Deepwater Horizon rig exploded on April 20 unleashing the worst oil spill in US history, would be ready to deal with well blowouts within 18 months.

One of BPs most vocal critics, Democratic Congressman Ed Markey, said the proposal did not go far enough.

"While this could be a rapidly-deployed system, the oil companies must do better than BPs current apparatus with a fresh coat of paint," said Markey, who chairs the House Energy and Environment Subcommittee.

"The oil companies must also invest more in technologies that will prevent fatal blowouts in the first place."

The announcement came as big oil attempts to gain favor with the White House and convince the US government to end a moratorium on deepsea oil drilling, which was imposed in the wake of the BP disaster.

The venture was also a response to the intense criticism laid against the oil industry in the wake of the spill, with lawmakers charging that firms were not adequately prepared to mitigate a potentially devastating spill.