China's central bank said Friday that the country's foreign exchange reserves as of the end of the fourth quarter last year topped 3.18 trillion U.S. dollars, down 20.6 billion U.S. dollars from the previous quarter.

The net quarterly decrease was a rare case in recent years in the country, which is currently the largest holder of foreign exchange reserves around the world.

In breakdown, foreign exchange reserves increased by 72.1 billion U.S. dollars in October, but decreased by 52.9 billion U.S. dollars and 39.76 billion U.S. dollars respectively in November and December, according to data from the People's Bank of China (PBOC), the central bank.

However, on a year-on-year basis, the nation's foreign exchange reserves still expanded from 2.85 trillion U.S. dollars by the end of 2010.

The PBOC data released Friday also showed the country's yuan funds outstanding for foreign exchanges fell to 25.36 trillion yuan (4 trillion U.S. dollars) in December, down 100.3 billion yuan from November. The December data also marked the third monthly decline.