The six year deal will see npower provide M&S with 2.6TWh of renewable electricity from April 2009 - enough to ultimately power all of the retailer's stores and offices in England and Wales.
Under the contract, npower will supply M&S with electricity from its portfolio of renewable sources, which includes wind and hydro farms.

According to M&S the 'unique' contract also allows for a significant amount of the supply to be purchased directly from independent small-scale generators of renewables, meaning M&S can continue with its 'pioneering drive' to encourage the development of renewable electricity. 


Richard Gillies, director of M&S environmental initiative Plan A, said: "Securing this contract with npower is a major achievement for M&S."