By Susanna Twidale

LONDON, June 19 (Reuters) - Equnior EQNR.OL and Gwynt Glas, a joint venture between EDF Renewables UK and ESB, have won seabed leases to build floating wind farms in the Celtic Sea off the coast of Wales and South West England, The Crown Estate said on Thursday.

Britain is aiming to largely decarbonise its electricity sector by 2030 to reduce its reliance on fossil fuels and drive down cost and is seeking to increase offshore wind capacity to 43-50 gigawatts (GW) by the end of the decade, from around 16 GW at present.

“Floating offshore wind will be transformative for economic growth in Wales and the South West, unlocking thousands of jobs in places like Port Talbot and Bristol, bolstering our energy security and delivering industrial renewal,” Britain’s Energy Secretary Ed Miliband said in the Crown Estate press release.

The Crown Estate, which acts as manager of the seabed around England, Wales and Northern Ireland, said Equnior and Gwynt Glas had both won leases giving them the rights each to build 1.5 gigawatt (GW) floating wind projects in its latest seabed leasing round.

The companies will pay 350 pounds ($468.55) per megawatt per year for the leases, the Crown Estate said, meaning both groups will pay 525,000 pounds per year for the sites excluding VAT.

Floating wind projects can be installed in deeper waters than fixed-bottom foundations, harnessing stronger and more continuous wind to generate more power.

The Crown Estate is an independently run, commercial business, whose profits go to the Treasury but its profits are also used as the benchmark for the level of public funding for the Royal Family.

($1 = 0.7470 pounds)

(Reporting by Susanna Twidale; Editing by Michael Perry)

((susanna.twidale@thomsonreuters.com; +44 207 5424753;))