Updated at 3.50pm: Financial Secretary Antony Leung Kam-chung said on Monday the Government would lower its 2001 economic growth forecast because of the impact of the terrorist attacks in the United States. ''The external economy will certainly be affected. Hong Kong's short-term economic outlook is uncertain.'' Mr Leung said, after meeting business representatives on Monday. His comments follow recent heavy falls on world sharemarkets and a growing mood of economic pessimism since the September 11 attacks in New York and Washington. After the mainland, the US is the SAR's second largest export market. Mr Leung said the Government would lower its 2001 gross domestic product (GDP) forecast, ''but as to how much we will tell you when appropriate''. The Government on August 31 cut its full year GDP growth forecast from three to one per cent. It was its second revision of the GDP forecast this year, after lowering the forecast from four per cent in May. Some local banks reduced their 2001 forecasts for GDP growth to below one per cent soon after. GDP is the total value of goods and services produced in the domestic economy.