Vancouver-based Tuya is a privately held coal exploration and development firm operating a thermal coal property between Telegraph Creek and Dease Lake in northwestern British Columbia.
Colonial and Tuya shareholders have given green light for the transaction at meetings held on 19 March.
The companies have signed a deal for the transaction in January this year.
Under the deal, Colonial will issue 0.5 of its common share to Tuya shareholders for each Tuya share held.
Tuya expects approval from the Supreme Court of British Columbia at a hearing on 26 March 2015.
The transaction is also subject to other closing conditions, and is expected to be concluded on or about 31 March 2015.
Colonial owns projects in northeast coal block of British Columbia, which is said to host a number of proven deposits.
