Air Canada flight attendants' union would need to notify their intention by end of the day Tuesday if they intend to walk off the job on Saturday.

Air Canada flight attendants rejected the airline's proposal for binding arbitration on Tuesday and continued direct talks, the Canadian Union of Public Employees said on Tuesday.

Air Canada contract negotiations with its flight attendants have come to a standstill, which could result in the issuance of a statutory 72-hour strike or lockout notice occurring at 12:01 a.m. EST on Aug. 13. Canada’s largest airline explained it offered a 38% increase in compensation over four...