Developers of the project, which lies 13 kilometres off Llandudno in Liverpool Bay, are RWE Innogy, Siemens and Stadtwerke München.
The existing contractor Reef Subsea Power & Umbilical will complete the other 98.
Cable laying and installation will be carried out by CT Offshore’s cable laying vessel, Sia, which is already at Gwynt y Môr.
CT Offshore entered into an agreement for Fugro Subsea Services to bury the cables. Reef and CT Offshore will work simultaneously to install the array cables.
One-hundred and fourteen of Siemens 160 3.6MW turbines are in place. Generation started in August and 10 foundations are left to be installed.
Construction at the EUR 2 biilion farm is on schedule and due to be completed later this year.
Offshore wind installation company A2Sea is a majority shareholder - 63% - in CT Offshore and announced that it will enter into the company's management structure on 1 February.
Gwynt y Môr is expected to sustain more than 110 jobs from a new multi-million pound operations and maintenance base, which will be built in North Wales.