HONG KONG - HONG Kong's main stock index plunged more than 12 per cent on Monday, closing at it lowest point in more than four years amid deepening fears about the world economy and company profits.

The blue-chip Hang Seng Index tumbled 1,602.54 points, or 12.7 per cent, to 11,015.84 - its worst close since May 2004. The benchmark is off more than 50 percent this year.

The session's slide added to Friday's loss of more than 1,100 points, or about 8.3 per cent, amid last week's sell-off across Asia.

Monday saw further regional declines, with Japan's benchmark finishing at its lowest in 26 years.

The yen's recent surge was spooking many investors, and depressed corporate earnings and forecasts added to the gloom, analysts said.

'Markets are gripped by fear,' said Mr Benjamin Collett, head of hedge fund sales trading at Daiwa Securities SMBC Co. 'You actually feel sick watching this move.'

Hong Kong investors seemed little comforted by a move by the territory's de facto central bank to inject more money into the market, as financials suffered some of the day's biggest declines and hit levels not seen in years.

Blue-chip HSBC tanked almost 15 per cent to HK$75 (S$14.64). Leading lender Industrial & Commercial Bank of China Ltd, or ICBC, nose-dived more than 11 per cent to HK$34.95, while Bank of China plummeted 14.9 per cent to HK$1.71.

PetroChina, the region's biggest oil and gas producer, fell back 15 per cent to HK$4.25, and upstream producer CNOOC lost 13 per cent to HK$4.24. -- AP