Air Canada says customers booked on affected flights on Saturday and wishing to make alternate travel arrangements can do so without penalty.
Some flights were cancelled and many others delayed on Friday as a result of an apparent protest by workers facing job losses when a refuelling contract changes hands later this year.
A spokesman for the International Association of Machinists and Aerospace Workers said 30 of 47 workers scheduled for the Friday morning shift called in sick, while others refused to work overtime.
Bill Trbovich said about 20 of 56 workers showed up in the afternoon with one shift remaining to provide fuel for the rest of the day's flights.
A number of airlines are switching their refuelling business to Aircraft Service International Group in Toronto as of Oct. 1 and have already moved to Swissport in Montreal as of July 1.
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