Asda, the supermarket group owned by Wal-Mart, is to explore selling electricity to its customers through its power services company, Power4All, in a move that reflects its US parent's growing interest in energy.

Andy Bond, chief executive, told the Financial Times that in the "medium term" the retailer hoped to extend to Asda's customers a programme initially set up last year to provide its stores with "low-cost energy and energy from totally sustainable sources".