COMPLAINTS from big players on the Hong Kong stock market have increased the urgency to review the new trading system, which was installed on November 12 and will be officially inaugurated today. During trial runs of the Automated Trading and Order Matching System (AMS), international brokers have been dismayed to find that the deals they are planning are becoming all too obvious to rivals. The board lots, or parcels of shares, which are laid down for the system are too small, the brokers say. This has led to single firms finding their names up on the screen dozens of times as they try to execute a big order for a client. There are also complaints that the keying in of so many lines of information is wasting valuable time in brokers' offices. Stock exchange official Derek Tam yesterday said the order sizes would be reviewed after all stocks were trading by AMS early next year. Mr Tam said the stock exchange had been aware of the board-lot size matter even before it started to draw comments from industry members. He said the exchange had selected the 100 board-lot maximum because it wanted to make the system as simple as possible. There are now 49 stocks trading by AMS, after 27 counters migrated to the system yesterday. These stocks now account for about 50 to 60 per cent of daily trading volume. Mr Tam said the exchange would continue its cautious approach by having counters 51 to 100 join AMS in two weeks' time. However, he said it would be possible for the last 200 to 300 stocks to join the system at the same time in February. Among the other issues now being reviewed by the exchange is the size of the screens. which has drawn complaints from many traders who say they are too small. Mr Tam said the stock exchange was shopping around to see what was available and what type of screens could fit into the traders' booths. The exchange will hold a ceremony this morning on the trading floor to officially launch the $100 million AMS, which went live last month after two years of development.