The Football Association has confirmed energy giant E.ON will not be renewing its sponsorship deal with the FA Cup at the end of this season.
E.ON's four-year deal was understood to be worth £32m to the FA and a search will now begin for a new sponsor for the tournament.
An FA spokesman said: "The FA can confirm that E.ON's sponsorship of the FA Cup will come to a close at the end of the current 2009/10 season.
"The FA would like to thank E.ON for its investment into and support of the competition to date. We now look forward to taking the FA Cup sponsorship opportunity to the open market for the 2010/14 period."
E.ON said changes to its UK sponsorship strategy meant it was not pursuing a renewal of the FA Cup deal.
FA chiefs are confident that the market value of the competition remains high and that they will attract an equal or bigger deal for the next four-year cycle.
The FA has still to agree a deal for the TV rights for the FA Cup made available by the collapse of Setanta which has left the organisation facing a £70m shortfall.