The agreement covering production and trades employees was hammered out last week and is effective Aug. 1.
In a release issue late Friday night, Essar Steel Algoma says ratification of the agreement gives the business the stability it needs, while providing employees, customers and suppliers the security they need.
Details of the contract have not been released, however, the union had been seeking changes in workplace conditions as well as benefit and wage improvements.
Essar Steel is a multinational company based in India.
It acquired the formerly independent Algoma Steel and took it private in 2007.