E.On's backing of the FA Cup has lasted four seasons
The Football Association has said energy firm E.On will not extend its sponsorship of the FA Cup - reported to be worth £32m - after the 2010 final.
E.On had a high-profile, four-year deal with the competition, during which it tried to encourage fans to go "green".
"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," said the FA.
E.On said a new UK sponsorship strategy meant it was not pursuing a renewal.
"The FA would like to thank E.On for its investment into and support of the competition to date," said English football's governing body.
"We now look forward to taking the FA Cup sponsorship opportunity to the open market for the 2010/14 period."
It is believed the FA is confident about signing another big-hitting sponsorship deal.
The FA has yet to agree a deal for the television rights to the FA Cup that had been owned by broadcaster Setanta before its collapse this summer. It is estimated this has left the FA with a potential £70m shortfall.
E.On said it is pleased with the exposure the deal has brought the company.
"Our decision to end sponsorship of the FA cup was purely down to a change in sponsorship strategy. The FA Cup has been great in terms of developing the brand," said Alex Howells, sponsorship promotions executive at E.On.
E.On also has a sponsorship deal with the Football League, due to end next year. The company is yet to make a decision on whether it will continue its involvement with the league.
"It's a completely separate decision and we are keeping our options open at the moment," said Howells.
As part of its agreement with the FA, E.On had looked to reduce the carbon footprint of supporters during each FA Cup campaign.
The "Carbon Footyprint" plan encouraged fans to make energy-saving changes to cut their own emissions.
The company had hoped the campaign would offset the 45,000 tonnes of carbon dioxide produced by the world's most famous club football competition each season in order to make it "carbon neutral".
Emissions were calculated from the operational emissions of all participating clubs, the television emissions from viewers watching matches at home and the travel emissions produced by home and away fans.
In return for making pledges, fans had the opportunity to win prizes, including free coach travel to away games.