HONG KONG, Oct 14 (Reuters) - The Hong Kong Monetary Authority sold HK$4.6 billion ($593.55 million) into the market in New York trading hours on Tuesday after the local currency hit the strong end of its trading band, according to data released by the HKMA.

The aggregate balance - the key gauge of cash in the banking system - will increase by HK$10.9 billion including HK$6.3 billion sold in Hong Kong trading hours, to HK$304.6 billion on Oct. 15, an HKMA spokesman said early on Saturday.

The Hong Kong dollar is pegged in a narrow range of 7.75-7.85 to the U.S. dollar. The HKMA has been conducting sales in recent sessions to weaken the currency to keep it within that trading band. ($1 = 7.7500 Hong Kong dollars) (Reporting by Alun John; Editing by Sam Holmes)