The proposals could see between 147 and 440 turbines with a total capacity of up to 2.2GW installed in an area about 14km from the North Wales island of Anglesey and 34km from the Isle of Man.
The two companies are calling the project Rhiannon Wind Farm.
In March, Danish energy giant Dong bought into Centrica’s 4.2GW Irish Sea Round 3 zone, paying up to £40m ($62.5m)
