A federal appeals court in Manhattan has dismissed a lawsuit by a group of Queens residents seeking to stop a runway expansion at Kennedy Airport, saying their objections were unfounded or without merit.

The Eastern Queens Alliance, a coalition of civic groups representing thousands of residents of southeastern Queens, said the Port Authority's ongoing project to widen Runway 4L/22R and construct 728 feet of new pavement on the north end would put departing and arriving airplanes closer to homes, schools, churches and businesses. The coalition said jets taking off and landing would undoubtedly bring more noise and air pollution to neighborhoods already inundated with them.

In its lawsuit, the Eastern Queens Alliance alleged that the Federal Aviation Administration, which reviewed and approved the Port Authority's plan, was wrong to conclude that the project would not have a significant impact on the surrounding communities and to decline to conduct an environmental impact statement.

The three-judge panel of the Second Circuit Court of Appeals issued its decision Dec. 23, five days after the attorneys for the coalition, the Port Authority and the FAA went to court.

"We understand the concerns expressed by members of certain communities near the airport," the judges wrote. "Each of EQA's objections, however, was either forfeited because it was not brought to the agency's attention during the public comment period . . . or is unfounded based on our review of the record."

The coalition's chairwoman, Barbara E. Brown of Brookville, Queens, said she was surprised how quickly the judges made their ruling.

"They didn't provide any analysis . . . " Brown said yesterday. "It seems like the court took what the FAA said and rubber-stamped it."

Brown said the coalition is considering its options, including going to the U.S. Supreme Court, although she admitted it's highly unlikely the high court would hear this case.

The Port Authority had said its plan is necessary to meet design standards set by the FAA. The wider runway would accommodate larger aircraft.

The FAA requires runways to have a buffer zone to lessen the risk of damage to property and injury to passengers if an aircraft overruns, undershoots or is forced off the runway. The authority has until Dec. 31 to bring Runway 4L/22R into compliance."We are pleased with the decision," said Wyn Hornbuckle, a spokesman for the Department of Justice, which represented the FAA in court.