The union represents approximately 800 members that work in the company's mining, milling and smelting operations.
Members voted 67.8 per cent in favour of accepting the tentative agreement that was made right before the previous one was set to expire.
No details on the new agreement have been made available yet.
Peter Xavier, vice-president of Sudbury Integrated Nickel Operations, said the company is pleased to settle without work disruption.
"We believe that the new agreement is fair, competitive and represents a balance of interests in securing a deep mining future for Sudbury INO," Xavier said. "The highlights of the agreement with the Union include a competitive offer of wage increases in each year over a four-year term, defined benefit pension plan increases, and a ratification payment."