The world's top industrialized nations and leading oil consumers pledged Sunday to fight skyrocketing energy prices by increasing efficiency and accelerating investment in new technologies, while urging producers to expand production.

Energy ministers from the Group of Eight countries, joined by China, India and South Korea, voiced concerns over record oil prices and said both producers and consumers would benefit from greater market stability.

Ministers, meeting in the northern Japanese city of Aomori, focused Sunday on how they could diversify their energy sources to both control rising demand for oil and rein in emissions of greenhouse gases blamed for global warming.

"We simply must increase the level and breadth of investment all around the world," said US Energy Secretary Samuel Bodman. "That means promoting aggressive investment in renewable energy and other alternative energies technologies, as well as the development of tradition hydrocarbon resources."

The 11 nations, which account for 65 percent of the world's energy consumption, grappled with oil prices that have hit record highs. Prices made a massive 8 percent gain Friday to $138.54 on the New York Mercantile Exchange.

The G-8 countries, the United States, Russia, Japan, Germany, France, Italy, Canada and Britain, laid out ways of cutting their dependence on oil in a statement.

They pledged to launch 20 demonstration projects by 2010 on so-called "carbon capture and storage," which would allow power plants to catch emissions and inject them into underground storage spaces.

While that technology is still in its infancy, proponents say it could eventually allow the expanded exploitation of the world's abundant supply of cheap coal without polluting the environment and speeding global warming.