HSBC lowered China's 2012 GDP forecast to 8.0 percent from 8.4 percent and its 2013 forecast to 8.5 percent from 8.8 percent, as the latest economic indicators showed that the country is facing stronger-than-expected external impacts, the bank said in a report released on Monday.

HSBC attributed the current slowdown in China to cyclical forces such as slumping overseas demand and the impact of earlier tightening measures.

“China's export growth fell sharply in July to 1 percent, and the Manufacturing Purchasing Managers' Index, an indicator for export capacity, hit the lowest point since March 2009,” HSBC China's chief economist Qu Hongbin said in the report.

Rapid decline in exports might lead to less industrial output, export and corporate profits, and higher risk of unemployment as inventories pile up.

Qu said that although rising global food prices might raise the cost of pork, the Consumer Price Index would remain under 3 percent as the Producer Price Index declines and domestic demand recovers.

HSBC believes that Beijing will step up policy easing in the coming months to lift growth to above 8 percent in the fourth quarter of 2012, including another 25 basis points cut in interest rates in the third quarter and a further 200 basis points fall in the banks' reserve requirement ratios before the end of the year.

The report also said that China's potential growth rate will be 9 to 9.5 percent until 2015, and should average 8 to 8.5 percent between 2016 to 2020.