With its plan for reducing the interstate movement of air pollution blocked by recent federal appeals court decisions, the Environmental Protection Agency yesterday announced a scaled-back strategy to improve air quality in eastern states affected by polluting industries in other regions.

"The actions we are taking today are our best effort to ensure that people living in the eastern United States will receive public health protections . . . in the spirit of the Clean Air Act," said EPA Administrator Carol M. Browner.

Under the plan announced by Browner yesterday, the EPA would effectively sidestep parts of two damaging court rulings last month by separate three-judge panels of the U.S. Court of Appeals for the District of Columbia.

The first ruling overturned tough new air quality standards for smog and soot. The second suspended implementation of a rule requiring 22 states and the District of Columbia to submit plans by September for restricting emissions of nitrogen oxide, pending the outcome of a lawsuit challenging the rule. Nitrogen oxide is a key ingredient in smog that is blown eastward by prevailing winds from many large Midwestern power plants and industrial boilers.

The original plan, announced last September, would have reduced nitrogen oxide emissions in the 22 states and the District by 1.1 million tons annually, or about 28 percent. Under the scaled-back version announced yesterday, the EPA would revert to an earlier process under which eastern states had petitioned for emission reductions in 12 polluting states. It would use a less stringent emissions measuring standard than the one tossed out by the appeals court panel and is designed to achieve emissions cuts of about 717,000 tons per year, about 60 percent of the more comprehensive regional plan.

Industries in 10 states -- Illinois, Wisconsin, Connecticut, Rhode Island, Massachusetts, Mississippi, Alabama, Georgia, South Carolina and Tennessee -- would escape new restrictions unless the Clinton administration is successful in appealing the recent court decisions. The District and 12 other states -- Delaware, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Pennsylvania, West Virginia and Virginia -- would have to restrict nitrogen oxide emissions by 2003 if the revised plan is adopted later this year.

"This will not provide as much public health protection as the regional plan," Browner said. She pledged, however, to revert to the more comprehensive strategy if the administration prevails in court. "The administration does intend to pursue any and all legal avenues available to us," she said.

"This is not the preferred path," Browner said. "The court has taken that preferred path away from us. But we felt we still have an obligation to people for cleaner air. When we prevail in court, we will go back to the original path."

The 22-state plan for reducing nitrogen oxide emissions was challenged in court by several Midwestern states and power plants. A spokesman for the utility industry said yesterday it would reserve comment on the revised plan until the EPA completes formal rulemaking on it next fall.

Of the two recent court of appeals decisions, the first one, relating to new restrictions on smog and soot, is potentially the most far-reaching for the EPA. In ruling that the EPA had taken actions that amounted to "unconstitutional delegations of legislative power," the court appeared to sweep away powers exercised for many years by the agency.

Browner continued yesterday to assail the reasoning of the three-judge panel in that case, calling the decision "illogical" and "bizarre."

The plan Browner announced yesterday would not counteract that ruling, which the EPA plans to appeal.