The Singapore Exchange (SGX), which like its home country prides itself on relentless efficiency, suffered an embarrassing glitch yesterday as two of its main indices showed the wrong figures for almost two hours. Although officials said the computing error did not affect the pricing or trading of individual stocks, the incorrect headline indices confused some traders about the market's overall direction, which was wrongly shown as being almost 3 per cent into negative territory. A spokesman for the SGX said that the errors were caused by feeding in the wrong currency-conversion data for the index constituent stocks priced in US dollars. Nine of the 45 lead index constituents are priced in US dollars and include the quartet of Jardine companies: Hongkong Land, Jardine Strategic, Jardine Matheson and Dairy Farm International, all of which used to be listed in Hong Kong. There were incorrect figures for the Straits Times Index (STI) and the Business Times Singapore Regional Index from 9.51am to 11.47am, the official said. The error stemmed from the foreign-exchange data feed received by SGX which is taking steps to prevent a similar occurrence. The value-weighted STI is the market's key gauge. Based on the prices of the market's 45 biggest stocks it aims to represent at least 60 per cent of the overall market's capitalisation and more than 70 per cent of its daily turnover. Its lead members include Singapore Telecommunications and Singapore Airlines, which are listed in local currency. Launched in October 1996, the Business Times-Singapore Regional Index comprises 38 stocks that have a substantial exposure to the Asian region; a market capitalisation of at least S$280 million and, a free float of at least 25 per cent.