DALLAS (AP) _ American Airlines flight attendants who crossed picket lines during the five-day November strike face fines, suspensions or other sanctions, their union said Sunday.

The Association of Professional Flight Attendants said that between 5 percent and 10 percent of its 21,000 members have quit the union. But members who worked during the pre-Thanksgiving strike face sanctions.

''The board affirmed today that it will take appropriate action ... but did not determine specific action,'' said union spokesman Randy Edwards. ''It could involve a suspension from the union or expulsion from the union. If they are officeholders, it could involve removal from office, or they could be fined.''

The vast majority of the union's members supported the Nov. 18-Nov. 22 walkout, which ended after President Clinton asked the carrier and the flight attendants to submit to binding arbitration of their contract dispute.

Talks are continuing between the two sides.

''Some said they didn't agree with the strike, others sided with the company. Some were afraid of losing jobs, others their medical benefits,'' said Edwards. ''... The company was actively encouraging people to resign before the strike to avoid penalties from the union.''

American denied that it tried to sway attendants' decisions.

''We were responding to several questions from flight attendants on a question-and-answer hot line,'' said company spokesman Gus Whitcomb. ''They had requested information on their rights on belonging to a union. We provided that to them.''

''But we did nothing to either encourage or discourage membership or any action concerning the strike. That was a decision left up to each and every individual,'' he added.

Whitcomb said the company would not comment on the union's decision to discipline nonstrikers.