NEW YORK (AP) _ Pan American World Airways said Thursday it has taken precautionary measures in the ''unlikely event there is a job action'' by flight attendants this weekend.

Earlier this month, the Independent Union of Flight Attendants put a tentative contract to a vote and sealed mail ballots were to be counted Friday in Millbrae, Calif.

The union leadership did not recommend passage and called the pact ''highly concessionary.''

If the vote is negative, a strike could be called at any time as the membership authorized one long ago, according to Russ Gladden, communications coordinator for the 5,800-member union. ''I don't know if a strike will be called.''

''It is impossible to predict the outcome,'' Gladden said. ''It could be close or it could be a blowout.'' He predicted a very heavy turnout.

Pan Am spokesman Jeff Kriendler said the airline is ''prepared for any eventuality.''

''In the unlikely event that there is a job action, we have been preparing. But we do not believe there will be one,'' he said.

The airline has said it intends to continue 100 percent of its operations in the event of a strike. Managers have been trained ''to improve our standby capabilities,'' Kriendler said.

''We have hired 440 new flight attendants who had been given temporary employment back in the spring. They are going to be used in anticiption of the ratification of the contract and the early out provision.''

The early out provision provides a package of wage and benefits incentives for early retirement, Kriendler said.

''We anticipate there will be a good number of flight attendants who will opt for the early out program,'' he said.

The replacements were hired at much lower salaries than those paid to union members. The two-tier wage scale is one of the concessions allowed under the proposed new contract.

After around the clock bargaining to avert a strike, the pact was initialed on April 1. But when union officials read the final draft, they disputed several clauses. The disputed language was submitted to the National Labor Relations Board, which on July 10 issued an inconclusive ruling.

The union then decided to put it to a membership vote.

Among other concessions, the contract calls on the union to drop all outstanding grievances and legal challenges. The union leadership says it never agreed to that. In one case, a federal court has ordered the airline to pay back wages. They would not be required to do so if the contract is ratified.