Npower signed a three-year deal, believed to be worth around £21million, to replace Coca-Cola in 2010 but have confirmed to that they are bringing their partnership to an end.
"We can confirm that we will not renew our sponsorship of The Football League when the current season ends at the end of May," a statement read.
"During the last three years, we have enjoyed a hugely successful relationship with The Football League and have engaged the passion of thousands of football fans across the country."
No announcement is due on who will replace npower as the league's principal sponsor.
"The contract comes to an end at a time when npower is in the process of reviewing and defining brand positioning and marketing strategy to help shape future direction, following a restructure which saw the generation arm merge into a wider pan-European company," the statement continued.