Four big international companies, including the oil giant Exxon Mobil, said yesterday that they would give Stanford University $225 million over 10 years for research on ways to meet growing energy needs without worsening global warming.

Exxon Mobil, whose pledge of $100 million makes it the biggest of the four contributors, issued a statement saying new techniques for producing energy while reducing emissions of heat-trapping greenhouse gases were ''vital to meeting energy needs in the industrialized and developing world.''

Many scientists and environment experts said the Stanford project was likely to be a valuable new assault on a serious environmental problem. But some environmental campaigners said Exxon, which has long expressed skepticism about risks posed by climate change, was mainly trying to improve its image.

In 2000, Ford and Exxon Mobil's global rival, BP, gave $20 million to Princeton to start a similar climate and energy research program.