HONG KONG -- The Hong Kong Monetary Authority (HKMA) announced on Wednesday that the city's total assets of the Exchange Fund increased by HK$153.6 billion to HK$2.6463 trillion at the end of January, on December 2011.

The Monetary Authority said that foreign-currency assets increased by HK$78.6 billion and Hong Kong dollar assets increased by HK$75 billion.

The rise in foreign currency assets was mainly due to purchases of foreign currencies with Hong Kong dollars, valuation gains on foreign currency investments, increases in unsettled purchases of securities and Certificates of Indebtedness, said the HKMA.

The Currency Board Account shows that the Monetary Base at the end of January was HK$1,091.2 billion, up HK$15.2 billion, or 1.4 percent, from the end of December 2011. The rise was mainly due to an increase in Certificates of Indebtedness.

Backing Assets increased by HK$14.4 billion, or 1.2 percent, to HK$1,186.4 billion.

At the end of January, the backing ratio decreased from 108.92 percent to 108.72 percent.