Hong Kong stocks slumped nearly 2.3 per cent Thursday as pessimism gripped the market amid concerns over the earnings outlook of some big companies.

The Hang Seng Index lost 492.43 points to end the day at 20,972.29 points, down 2.29 per cent on Wednesday's close. Turnover was a relatively light 66.7 billion Hong Kong dollars.

The fall in prices comes after a strong week and was led by heavyweight stocks Esprit Holdings, PetroChina and China Mobile which disappointed investors with their earnings.

On Monday, the index saw its biggest one-day rally for five months, jumping 3.5 per cent.