New York ? The city’s bus and subway workers Friday put off a potentially crippling strike until at least next week, leaving a cloud of uncertainty hanging over New York at the height of the Christmas rush.

Negotiators for the 33,000-member Transit Workers Union and the Metropolitan Transportation Authority failed to agree on a new contract when the old one expired at midnight Thursday, but the trains and buses kept running, and the union set a new deadline of 12:01 a.m. Tuesday.

Many New Yorkers did not know until they awoke Friday whether they would be able to ride the buses and subways, which carry nearly 7 million passengers a day. Commuters were relieved, but the uncertainly of the down-to-the-wire negotiations left some exhausted.

The last bus and subway strike in New York was an 11-day walkout in 1980 that paralyzed the nation’s largest mass transit system.

The new deadline raises the possibility of a strike in the middle of the last shopping week before Christmas, instead of on a drizzly Friday that many commuters could have converted into a three-day weekend.

The transit workers are prohibited by state law from striking and run the risk of heavy fines and lawsuits if they walk off the job.