The Department of Energy, despite protests from its own environmental experts, has quietly proposed an amendment to petroleum pricing regulations that could lead to an increase of four cents per gallon for motorists buying gasoline at the pump.

A congressional watchdog subcommittee and a consumer group yesterday attacked DOE for attempting what the Center for Auto Safety called "an end run" around opposition to the proposed deregulation of gasoline.

Consumer and environmental groups have balked at DOE attempts to deregulate motor gas, claiming the spread between the price of unleaded and leaded gasoline would grow so much, many people would illegally use the dirtier buy cheaper leaded gasoline, and contribute to polluting the air.

Some recent studies have shown that up to 15 percent of all motorists required to use unleaded gas in their cars instead used leaded, because it is already between four and 10 cents cheaper.

An earlier DOE attempt to deregulate gas was delayed when the Environmental Protection Agency balked at the fact that no environmental impact study had been done to gauge how much fuel switching would take place.

Yesterday, the House subcommittee on oversight and investigations sent a scathing letter to David Bardin, administrator of DOE's Economic Regulatory Administration, criticizing him for frustrating the committee's efforts to "fully analyze DOE's gasoline price increase."

Subcommittee Chairman John Moss (D-Calif.) accused Bardin of withholding key internal DOE Documents questioning the proposed price increases, which Moss called "inflationary" and said "would cost consumers an estimated $4 billion per year."

The DOE-proposed amendment would allow refiners to allocate a greater proportion of increased crude oil and nonproduct costs directly to gasoline prices.

Moss obtained the memos indendently, however, and released them to the press. He drew particular attention to a draft memo from Ruth Clusen, DOE assistant Secretary for the environment, protesting DOE's failure to prepare an environmental assessment of the proposed regulation, and challenged most of Bardin's assumptions about the effects of the proposed amendment.

"In particular," Moss said, "the draft memo pointed out the lack of any quantitative analysis concerning the magnitude of the price increase of unleaded gasoline."

In a letter sent to energy secretary James Schlesinger yesterday, the Center for Auto Safety, a Ralph Nader-affiliated group, said it was "shocked not only at the DOE's continued flouting of the National Environmental Policy Act, but also at the department's base duplicity in promoting a multibillion dollar ripoff of the American public by the oil industry."