An electric utility trade association charged yesterday that reducing acid rain would produce huge increases in consumers' electric bills, but environmental groups disputed those findings.

The Edison Electric Institute said that some of the legislation before Congress to control acid rain could increase electric bills by as much as 50 percent in certain states.

The EEI study, which was based on answers from utilities in 24 states, concluded that such legislation could add as much as $938 to a household's electric bills in the hardest hit areas in the industrial Midwest. Utilities predicted the largest increases in Indiana, Michigan and Ohio.

Virginia Electric and Power Co. estimated that reducing the pollution linked to acid rain would raise bills by about 7 1/2 percent, or $107 a year, for the average user.

Elizabeth Barratt-Brown, a specialist on acid rain for the Natural Resources Defense Council, said that studies by government agencies, including the Environmental Protection Agency, the congresssional Office of Technology Assessment and the Congressional Research Service, predicted that costs would increase bills by from 2 1/2 percent to a maximum of 10 percent in one state.

"The Tennessee Valley Authority has reduced emissions by 50 percent for an increase in costs of 6 to 8 percent," she said. Barratt-Brown called the EEI study a scare tactic and said it was timed to divert attention from a major study of acid rain by the National Academy of Science, which is scheduled to be released on Thursday.

Acid rain is produced in the atmosphere by a mixture of sulfur dioxide, nitrogen oxides and moisture. It has been blamed for damage to bodies of water, forests and crops and buildings. Proposals to limit the amount of sulfur dioxide emitted by coal-fired utility plants are designed to reduce the amount of acid rain.