South Korea's foreign currency reserves kept a record-breaking trend for the third straight month as the weak U.S. dollar increased the conversion value of non-dollar assets, central bank data showed Friday.

Foreign reserves reached a fresh high of 405.51 billion U.S. dollars as of end-January, up 1.82 billion dollars from a month earlier, according to the Bank of Korea (BOK).

The record-breaking trend continued for three months in a row as the dollar weakness raised the conversion value of non-dollar assets.

The British pound appreciated 3.3 percent versus the dollar, and the Australian dollar rose 2.8 percent to the dollar.

The dollar index, which gauges the greenback's value against six major peers such as the euro, the pound, and the Japanese yen, declined 1.1 percent last month.

The country's foreign reserves were composed of 380.3 billion dollars of securities, 14.9 billion dollars of deposits, 4.79 billion dollars of gold bullion, 3.39 billion dollars of special drawing rights and 2.18 billion dollars of IMF positions.

South Korea was the world's eighth-largest holder of foreign reserves as of the end of December.