Great Yarmouth-based 3Sun will support MHI Vestas with the electrical and mechanical completion of the project, currently under construction in UK North Sea waters.
The firm will provide technicians to help complete the installation of 73 V112-3MW turbines, located eight kilometres from the Yorkshire coast, north-east England.
It is the first time 3Sun will work with Vestas on an offshore project, although the two companies previously worked together on onshore projects.
Humber Gateway, developed by German utility E.on, is expected to be made operational by spring 2015.
In May, 3Sun secured a contract with Siemens to provide offshore installation services in the UK until 2016.