The Hong Kong Monetary Authority (HKMA) sold a total of HK$9.347 billion ($1.21 billion) worth of Hong Kong dollars on Monday as the currency hit the strong end of its trading band.

The de facto central bank sold HK$1.426 billion ($184 million) and HK$3.658 billion ($472 million) during New York trading hours after selling HK$4.263 billion ($550 million) during Asia trading, according to data released by the HKMA.

The aggregate balance - the key gauge of cash in the banking system - will increase to HK$113.817 billion ($14.69 billion) on June 10, an HKMA spokesman said early on Tuesday.

The Hong Kong dollar is pegged at 7.75 to 7.85 to the U.S. dollar and has at times traded closer to the stronger end of the limit in recent weeks despite rising political uncertainty.

(Reporting by Noah Sin and Twinnie Siu; Editing by Kevin Liffey and Kim Coghill)