Asian stocks slumped on Thursday in response to another fall in the US markets as mortgage lender Countrywide Financial and a fund linked with buyout firm Kohlberg Kravis Roberts & Co were hit by credit concerns tied to the subprime mortgage crisis. Hong Kong's Hang Seng Index fell 3.3% while Japan's Nikkei 225 and Korea's Kospi Composite dropped 2% and 6.9% respectively, the Wall Street Journal reported. The Shanghai Composite Index lost 2.14%. Jim O'Neill, head of global economic research at Goldman Sachs, said it was time to start asking if what began as a meltdown in one part of the US bond market was going to affect global growth. The IMF forecast three weeks ago that a slowdown in US growth would be balanced out by strong gains in China and India. Although there is likely to be a fall in US imports from China, O'Neill and other economists remained confident that the country – recently buoyed by its strongest retail sales figures in three years – would continue to spend.