Hong Kong stocks plunged for a third day, with the benchmark Hang Seng index falling 7.3 per cent in the first minutes of the stock market opening on Tuesday, dpa reported. But by 11 am (0300 GMT) the Hang Seng index had recovered slightly to 19,173.08 points, a drop of 6.43 per cent, or 1,317.49 points, from Monday's closing level. Tuesday was the first time the index had fallen below the 20,000 point mark since July 7 last year. The sell-off followed a wider contagion as Asian stock markets continued to suffer heavy selling in the wake of last week's US credit downgrade and fears of a second dip to the recession. Analysts said Asian markets were reacting to Monday's losses on Wall Street which was the first trading day since ratings agency Standard & Poor's downgraded American debt. The Dow Jones Industrial Average on Monday plunged 634.76 points, or 5.5 per cent, the worst drop since December 2008.