British energy regulator Ofgem has announced a shortlist of six bidders competing to connect nine offshore wind projects to the grid.

The annoucement is part of the first stage of a programme to connect up about 33GW by 2020.

The first stage will connect up to 2GW of renewable electricity, enough to power about two million homes, with the winners to be announced in May 2010.

Ofgem said the links were worth over £1bn ($1.6bn). It said the first round had attracted strong competition, with shortlisted bidders including National Grid and Balfour Beatty.

The news follows four bidders pulling out of the process last month.

It is the first phase of a £15bn programme to ensure links to offshore wind farms. Britain is adding to its offshore wind farms in its effort to source about a third of its electricity from renewable sources, reports Reuters.