The dealers closed down the computer system at Pakistan's main bourse. They smashed up parts of the building and attacked stock exchange officials.

Correspondents say the dealers managed to prevent police entering the premises before the authorities were able to regain control.

Although no-one was hurt in the incident, the stock exchange was closed and will not resume trading until repairs have been carried out.

Fear of redundancies

The head of the stock exchange, Shahid Gaffor, said the violence had been unfortunate but insisted that the new system would still be set up.

The traders are concerned that the new computer system will lead to redundancies.

There are more than 600 floor agents at the Karachi stock exhange.

The vast majority of the companies listed on the exchange have already switched to the automated system over the past few months. There were just three companies left which were still traded on the open outcry system for which so many agents are needed.

But correspondents say these three - ICI, the power company HABCO, and Pakistan Telecommunication Ltd - are by far the biggest, accounting for 95% of the turnover of the exhange.

On Monday evening, the board of directors at the exchange finally decided to switch these companies as well to make the Karachi exhange fully automated.

Even though many of the agents probably will lose their jobs, the directors had not expected the decision to lead to violent protests.