Air Canada and the Canadian Union of Public Employees reached a tentative labour agreement in the early hours of Tuesday, ending a four-day walkout by roughly 10,000 flight attendants that had crippled Canada’s largest airline during the peak summer travel period. The union said the deal was struck at 4:23 a.m. Eastern after nine hours of mediated talks and will be put to members for ratification. The strike, which began on Saturday, forced the carrier to ground about 700 flights a day and disrupted travel plans for more than 100,000 people daily—roughly half a million passengers in total—according to the airline. Ottawa had intervened on Sunday, directing the Canada Industrial Relations Board to order employees back to work under section 107 of the Canada Labour Code, but cabin crews continued to picket until a compromise was reached. Pay for unpaid ground duties such as boarding and a wider wage package were at the heart of the dispute. Air Canada had offered what it said was a 38 percent boost in total compensation over four years, including a 25 percent raise in the first year, while CUPE argued the proposal fell short of inflation and industry standards. Specific terms of the new accord were not disclosed. Air Canada said flights would begin ramping up immediately but warned it could take several days to restore its full schedule. The tentative deal eases pressure on the carrier, which normally transports about 130,000 passengers a day and had warned of extended disruptions if the standoff dragged on.