Beijing - China's main stock market plunged by nearly 4.6 per cent on Tuesday after disappointment at the scale of bank interest-rate cuts.

The key Shanghai Composite Index, which tracks shares traded in local and foreign currencies, lost 90.53 points, or 4.5 per cent, to end the day at 1,897.23 points.

The smaller Shenzhen Composite Index also lost 5.6 per cent of its value on Tuesday, closing at 587.21 points.

The falls pushed Chinese shares to a three-week low, after analysts had expected an interest-rate twice as large as what the People's Bank of China announced late Monday.

The bank cut interest rates for the fifth time in three months, but lowered the one-year base lending rate by only 0.27 percentage points to 5.31 per cent.

Shares in petrochemical, insurance, shipping and real estate firms were among Tuesday's biggest losers, the Shanghai Daily newspaper reported. (dpa)