BEIJING - 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, down $20.6 billion?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 in October, but decreased by $52.9 billion?and $39.76 billion 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 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) in December, down 100.3 billion yuan from November. The December data also marked the third monthly decline.