The independent science panel's first report, released in July, was seen as a key element in the national debate over whether stricter mileage standards should be mandated to save millions of barrels of petroleum.

The report concluded U.S. automakers could increase the fuel efficiency of sport utility vehicles, pick-up trucks, minivans and cars by 16 percent to 47 percent over the next 10 to 15 years.

The original report issued on July 30 "still stands," said William Colglazier, executive officer of the academy.

But the academy will issue a narrower, so-called "letter report" to consider "minor revisions" to its earlier findings, he said.

AUTOMAKERS SEE DOUBLE-COUNTING

Led by the Alliance of Automobile Manufacturers, auto companies complained the report double-counts the effects of available mileage-reducing technologies.

That in turn inflated the target figure for the science panel's calculated reductions, the industry contends.

The new report rose directly from those concerns, Colglazier said. "We thought it was something we had to look at," he said.

"The ... report should be revised to reduce the benefit of technologies where it is overstated and eliminate infeasible technologies from the analysis," the alliance stated in its presentation last week.

David Friedman, an analyst with the Union of Concerned Scientists, called the academy's decision to prepare a second report "an unprecedented bow to industry pressure."

The activist group pressed the science panel to hold the line on its initial findings. "The issues brought up by industry do not justify any modifications or justifications," Friedman said.

DOE SUPPORTS FIRST REPORT

A Bush administration official supported the original report and questioned whether notable improvements would come from a new report.

"We thought the report was pretty good as it was written," Barry McNutt, a policy analyst for the U.S. Energy Department, told the science panel at a public hearing last week. He urged the academy to wrap up the new report quickly.

"This issue has existed for 23 years," McNutt said. "Resolving it will be very difficult and will have to get down to nuances."

In August, the Republican-led U.S. House approved a broad energy package to boost U.S. supplies of oil by opening drilling in the Arctic National Wildlife Refuge.

Some Democrats and environmental groups, however, contend that a better approach is to require automakers to improve the mileage of sport utility vehicles and minivans, which now account for more than half of all new vehicles sold each year.

Automakers say fuel efficiency is mostly improved through lighter weight vehicles, which can be more dangerous to passengers.

The U.S. Senate has yet to finish writing its energy bill.

The July report addressed so-called Corporate Average Fuel Economy, or CAFE, standards, adopted by Congress in 1975 after the Arab oil embargo. They require passenger cars to get an average 27.5 miles per gallon and light trucks to get 20.7 mpg.