Adidas, the world's second largest sportswear maker, has reported a loss for the last three months of 2012, mainly owing to impairment charges relating to its Reebok brand.
The group reported a fourth quarter operating loss of 239m euros ($311m; £207m), after it adjusted assumptions about the rate of growth at Reebok.
It wrote off 265m euros to reflect lower growth predictions for the brand.
Last year, Adidas cut its 2015 sales target for Reebok by a third.
For 2012, Adidas' operating profit fell by 3.4% to 920m euros.
Reebok's poor performance has been largely in the Americas, including North America, Brazil and Latin America.
The brand, which was bought by Adidas in 2005, has struggled to make an impact with its sports shoes that are designed to boost muscle tone.
The second quarter of last year also saw problems at Reebok after a fraud was discovered in its Indian division.
The brand's troubles were compounded by a US National Hockey League players' dispute which meant few games were played during the season.
Adidas is trying to reposition the brand as clothing to be worn for exercise such as yoga and dance.
Despite Reebok's woes, Adidas' chief executive Herbert Hainer, said the company had performed well: "2012 has been another successful year for the Adidas group.
"Our products and brands were again at the fore, not only being the most visible at the year's major sports events, but also enjoying several important market share victories along the way."
The year included two major world sporting events, the Olympics and the Euro 2012 football championships