HONG KONG, May 8 (Reuters) - Hong Kong's Exchange Fund, which is used to back the Hong Kong dollar, posted an investment income of HK$97.9 billion ($12.47 billion) in the first quarter of 2023, the Hong Kong Monetary Authority (HKMA) said on Monday.

The figure compared with a HK$48.8 billion investment loss in the same period a year earlier, and an adjusted HK$73.4 billion investment income in the fourth quarter of 2022.

The HKMA is the key manager of the Exchange Fund, which is under the control of the financial secretary and invests in equities, bonds, foreign exchange and other securities and assets.

($1 = 7.8480 Hong Kong dollars) (Reporting by Twinnie Siu and Donny Kwok; Editing by Christian Schmollinger)