The D.C. Board of Elections has made a new effort to keep an educational tax credit initiative off the Nov. 3 ballot by asking the full D.C. Court of Appeals to overturn a ruling that ordered a vote.

In a petition filed late Wednesday the Elections Board said a panel of three appeals court judges had ruled improperly that the proposal, which received more than 27,000 signatures in its petition drive, should be placed before city voters.

The three judges -- Frank Q. Nebeker and Stanley S. Harris, with Julia Cooper Mack dissenting -- announced their ruling in a one-sentence order last Friday, but have not yet filed written opinions giving the reasons for their decision.

Earlier, the Elections Board had ruled that 82 percent of the signatures on the petitions had been collected by out-of-towners who were not properly registered D.C. voters. It refused to put the initiative on the ballot.

Yesterday Albert J. Beveridge III, the Elections Board chairman, said the board had asked the full nine-member court to rule on the issue because of its importance to the city. "The integrity of the initiative process is at stake," Beveridge declared.

In its petition for a new hearing, the board added that the court should normally defer to its decisions as long as they are reasonable.

Under the court's rules, five of its nine judges must agree to a hearing by the full court, an action they rarely take, though Beveridge was hopeful they would do so in this case.

But H. Richard Mayberry, the lawyer for the tax credit proponents, asked the judges to turn down the appeal request, arguing that it is premature without written decisions by the three-judge panel.

Despite the appeal, Beveridge said the Elections Board is going ahead with plans for the vote and has ordered sample ballots with the measure included. The board told the appeals court that because of the city's computerized voting system the question could be removed from the ballot as late as just one day before the election.

Charles M. Pike Jr., campaign manager for the D.C. Committee for Improved Education, the pro-tax credit group, said the new appeal "will have absolutely no effect on our campaign."

"I don't take it seriously," Pike said, "because I don't think it's very likely that anything will really happen before the election. We assume it's going to be on the ballot."

Under the proposal, taxpayers would be allowed to deduct up to $1,200 per pupil from their D.C. income taxes for expenses at either private or public schools.

The initiative committee, which is a local off-shoot of the National Taxpayers Union, argues that the measure will upgrade education by giving parents more choice in their children's schooling and will particularly help low-income parents who would be able to receive tax credit contributions from others.

Foes of the measure, led by City Council Chairman Arrington Dixon and school superintendentFloretta McKenzie, charge that it will take large sums from the city treasury and gravely harm the city's public schools. They say it will mainly benefit the well-to-do who already have their children in private schools.