Umbro, which supplies uniforms and other equipment to England's national soccer team, said Thursday that its business will suffer from the team's failure to qualify for the European Championships.
Umbro issued a trading statement following Croatia's 3-2 victory over England, which eliminated England from the competition.
Umbro said sales of England replica shirts had been disappointing recently.
"The reduced levels of England home jersey sell-through at retail in 2007 and England's failure to qualify for the European Championships will have some effect on revenues in the current financial year," Umbro informed the London Stock Exchange.
"The effect on 2008 revenues, though still unclear, will be more pronounced due to a substantial reduction in our expected sales volumes for the new away jersey."
Umbro said the situation affirmed its belief that it must grow in international markets, a strategy it said would be assisted by Nike's proposed friendly takeover which values Umbro at 285 million pounds (397 million euros; $588 million).
Umbro said details of the Nike offer would be submitted to shareholders on Friday.