Hobbled by the credit crisis at home, Citigroup has limped through nine months in the red, reporting a $2.5 billion quarterly loss on Friday.

But across the financial company’s global empire, which spans more than 100 countries, similar tremors may be starting. In countries like Mexico, Brazil and India, loans in areas like home mortgages and credit cards are beginning to sour, as they have in the United States.

So far the problems are small. And Citigroup executives, who have spent months trying to turn the company around, say it is too soon to tell how much the problems might spread. The troubles hint at what could be in store for other American companies that rely on earnings from overseas, particularly when times are lean at home.

“We have clearly had some deterioration in credit internationally,” said Gary L. Crittenden, the chief financial officer of Citigroup. “That’s not isolated to Citigroup, that’s a broader question.”