The majority of the shares were bought from Belgian investment companies Ecotech and Socofe.
RWE Innogy also acquired 6.5 per cent of C-Power from shareholders including EDF Energies Nouvelles, Nutsbedrijven Houdstermaatschappij and DEME.
C-Power is developing and constructing the Thornton Bank wind farm off the Belgian coast.
According to RWE,
The wind farm will have an installed capacity of up to 300MW and is expected to produce around 1,000GWh of electricity per year, which is claimed to be sufficient to meet the requirements of about 600,000 people.
It will be equipped with 60, five-megawatt class turbines.
The first six turbines have been installed as part of a pilot phase and another four project phases are due to follow by 2013.
According to RWE, the profitability of the wind farm is safeguarded by a certificate system whereby Belgian electricity utilities have to contribute a percentage of renewable energies to their energy mix or purchase a corresponding amount of certificates.
The minimum price of offshore wind certificates is €107 (£94.68) per MWh for the first 216MW and €90 per MWh for capacity exceeding 216MW.
‘Thornton Bank is one of the first offshore wind farms worldwide, built at a depth of up to 28m up to 30km off the coast,’ said Prof Fritz Vahrenholt, chief executive officer of RWE Innogy.
‘This is why the investment provides us with an excellent opportunity to not only contribute, but also extend our experience significantly in the offshore sector.
‘This will benefit our ambitious development aims in the offshore sector.’
Michel Savonet, chief executive officer of Ecotech Finance, added: ‘We are particularly happy to see that the acquisition is pursued by a group with the reputation and experience of RWE.
‘Together with Socofe, we will continue to move the project forward and will use the proceeds from the sale to contribute to funding the second phase.’