Air Canada's unionized flight attendants reached an agreement with the country's largest carrier on Tuesday, ending the first strike by its cabin crew in 40 years that had upended travel plans for hundreds of thousands of passengers.

The airline said that it would gradually restart operations Tuesday but that a return to "full restoration may require a week or more."

The union representing 10,000 Air Canada flight attendants says it's reached a tentative agreement with the carrier and their strike, which had entered its fourth day, is over.