The companies also received clearances also from the competition authorities of a number of other jurisdictions, including Canada, Chile and Turkey.
Metso said it expects the completion of the combination to take place on June 30, 2020.
When merged, the new company will have 15,600 employees, and had illustrative 2018 combined sales and adjusted EBITA of €3.9 billion.
Metso shareholders will own 78% and Outotec shareholders 22% of the combined company.