NEW YORK, AUG. 22 -- The pilots union of Eastern Airlines today quit the bankrupt carrier's creditors committee, protesting what it called ''unscrupulous legal maneuverings'' by other creditors.

The Air Line Pilots Association (ALPA) withdrew just prior to a hearing on Eastern's efforts to have both the pilots and machinists unions removed from the committee because of alleged leaks of confidential information.

Eastern has accused the unions of using confidential information from the committee in a campaign to persuade travel agents not to book passengers on the financially beleaguered carrier.

The unions, which are among Eastern's largest creditors, had attempted to subpoena other members of the committee over the alleged leaks, but the subpoenas were quashed Tuesday by the federal bankruptcy court judge overseeing the airline's Chapter 11 bankruptcy proceedings, ALPA said.

''The withdrawal was precipitated by a series of unscrupulous legal maneuverings,'' the union said.

Some members of the creditors committee deliberately left town to avoid the subpoenas, the union charged.

When the bankruptcy judge quashed the subpoenas ''at the request of the corporate creditors, it became obvious that they needed a scapegoat to cover their tracks,'' said Capt. Skip Copeland, a union spokesman.

''Rather than submit as willing victims to this travesty, we decided to pull out in protest,'' he said.

The effort to remove the ALPA and the International Association of Machinists (IAM) from the committee was initiated by Martin Shugrue, who was appointed trustee to oversee Eastern in April, and supported by the creditors committee, said Joel Zweibel, a committee attorney.

''Evidence that they breached the confidentiality provision was overwhelming,'' Zweibel said. ''They went on a campaign to try to dissuade travel agents from booking passengers, using confidential information they got as committee members.''

The unions allegedly used information presented to the committee privately by Shugrue in May, Zweibel said.

Using information "portraying the airline in the worst possible light, they went to travel agents with a packet of material and said, 'See how bad things are? Don't book passengers on Eastern,' " Zweibel said.

The creditors committee has strict confidentiality rules that were ''simply disregarded,'' Zweibel said.

Eastern's unions representing pilots, machinists and flight attendants walked off the job in a bitter contract dispute in March 1989. The carrier filed for bankruptcy protection five days later. The pilots and flight attendants unions have since called off their walkouts, although the IAM remains on strike.