Nottingham Forest confirmed that Capital One will not be renewing their sponsorship of the club when the current agreement expires at the end of this season.
Capital One took the decision to end their six-year spell as major sponsor of The Reds.
The club have already begun the search for their successor and are in talks with a number of interested parties.
Forest's Chief Executive Mark Arthur said: "We have enjoyed an excellent relationship with Capital One - a relationship that we believe has been mutually beneficial to both parties.
"We know Capital One have not taken the decision to bring their sponsorship to an end lightly and I would like to thank them for their wonderful support."
Capital One have sponsored Forest since summer 2003, after striking a deal thought to be worth between £5m and £6m.
Chief executive Mark Arthur said: "We have enjoyed an excellent relationship with Capital One – a relationship that we believe has been mutually beneficial to both parties.
Justin Basini, head of brand marketing at Capital One said: "We have achieved a great amount with Nottingham Forest, both as the club's major sponsor and in the delivery of many joint community initiatives, but now feel it is time to move on."