Credit card usage in the United States rose in December last year for the first time in more than two years, indicating that consumers are becoming more confident on the economic conditions in the country.

Total credit outstanding in the US increased to $6.1 billion in December, boosted by an expansion in credit card usage, the Federal Reserve said on Monday.

Economists polled by Reuters had expected the consumer credit to rise by $2.3 billion in December 2010.

It's encouraging that lenders are at least allowing credit card spending to go up, but also it's not great that the only way that extra consumption can be financed is through credit cards rather than hiring income, said a Reuters report quoting Paul Ashworth, chief economist at Capital Economics.

Revolving or credit-card debt increased by $3.5 billion, posting an increase for the first time since August 2008.

Also, consumer borrowing rose for the third consecutive month in December helped by shopping during Thanksgiving and Christmas. Consumer credit contracted for 20 straight months, before posting monthly gains during Oct-Dec of 2010.

However, the consumer borrowing in December stood just 0.7 percent higher compared with three low reached in September 2010.