WASHINGTON - Environmental Protection Agency Administrator Stephen L. Johnson last night denied California's petition to limit greenhouse gas emissions from cars and trucks, overruling the unanimous recommendation of the agency's legal and technical staffs and dashing the hopes of 18 states that want to adopt the same standards.

Four days after the United States compromised under worldwide pressure to break an impasse at the U.N. climate conference in Bali, yesterday's decision demonstrated the Bush administration's determination to oppose any mandatory measures specifically targeted at curbing global warming pollution. It also set in motion a legal battle that EPA's lawyers expect to lose.

Pennsylvania, New Jersey and 16 other states, representing 45 percent of the nation's auto market, have adopted or pledged to implement California's emissions rules, which seek to cut vehicles' greenhouse gas emissions by 30 percent between 2009 and 2016.

In a telephone news conference last night, Johnson said the higher fuel-economy standards and increased renewable-fuel requirements in the new energy bill - approved by Congress yesterday and signed into law by President Bush just hours earlier - will do more to slow global warming than state-by-state tailpipe rules.

"The Bush administration is moving forward with a clear national solution, not a confusing patchwork of state rules, to reduce America's climate footprint from vehicles," he said.

The federal mileage standard is aimed at reducing gasoline consumption, which will reduce vehicles' overall "carbon footprint." California's rules would target total greenhouse gas emissions, including those from auto air conditioners.

Experts said tailpipe regulations are a more comprehensive way to address contributions to greenhouse gases.

Johnson said California standards would produce a mileage average of 33.8 mpg by 2016, while the federal law would require an average fleet fuel economy of 35 mpg by 2020.

California had been awaiting a decision for two years but EPA put it off while the Supreme Court considered whether it could regulate greenhouse gases. In a landmark ruling in April, the court said it could.

Since then, federal judges have twice rebuffed automakers' attempts to block state tailpipe regulations. The industry lobbied the White House and EPA as well.

Environmentalists and state officials lambasted the EPA's decision and pledged to sue.

"By refusing to grant California's waiver request for its new motor vehicle standards to control greenhouse gas emissions, the administration has ignored the clear and very limited statutory criteria upon which this decision was to be based," said S. William Becker, executive director of the National Association of Clean Air Agencies, which represents 48 states. "Instead, it has issued a verdict that is legally and technically unjustified and indefensible."

EPA's lawyers and policy staff had reached the same conclusion, said several agency officials familiar with the process. In a PowerPoint presentation prepared for Johnson, aides wrote that if he denied the waiver and California sued, "EPA likely to lose suit."

But if he allowed the state to proceed and automakers sued, "EPA is almost certain to win."

Rep. Henry Waxman (D., Calif.), who chairs the House Oversight and Government Reform Committee, vowed to scrutinize Johnson's ruling.

"EPA's decision ignores the law, science, and common sense," Waxman said in a statement. "The committee will be investigating how and why this decision was made."

California, which is allowed under the Clean Air Act to set its own air pollution policies as long as it receives a federal waiver, had never been denied in the Act's 37-year history.

William Reilly, who approved nine California waivers while serving as EPA administrator under President George H.W. Bush, questioned why the administration challenged the state's historical role as an innovator in air pollution policy.

"There's every reason to defer to California in making these decisions," said Reilly, who cochairs the bipartisan National Commission on Energy Policy, an energy group.

Speaking with reporters, Johnson said this waiver decision was "different" because climate change "is a global problem that requires a clear national solution."