Details of the tentative settlement were not immediately available.
Unifor says the deal covers hourly drivers, owner-operators, call centre staff, clerical, and warehouse workers at Loomis Express locations in B.C., Alberta, Saskatchewan, Manitoba, Ontario, New Brunswick, Nova Scotia and Prince Edward Island.
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The union says ratification votes will be scheduled in the coming days.
The members of Unifor Locals 114, 4050, 755, 4457 and 4005, have been working without a contract since March 31.
Loomis Express is owned by TFI International Inc.