Overall retail sales here rose by 6.8 per cent for the month compared to August, figures released by the Department of Statistics on Friday showed.

September was also a good month when compared to the same period last year: Sales rose 7.2 per cent year on year, according to the Retail Sales Index.

The figures left some economists scratching their heads.

Many expected that sales would be hit by spending cutbacks, since the turmoil that has roiled world financial markets began in the middle of the month, when investment bank Lehman Brothers went under and insurance giant AIG almost followed suit.

Citigroup called the figures 'surprising' in a report on Friday.

One of its senior economists, Mr Kit Wei Zheng, attributed the good performance to a surge in tourist arrivals for the world's first Formula One night race, held here from Sept 26 to 28.

'There may have been a temporary lift in spending during the F1 period. It would not have been very large, but there was something,' said Mr Kit.

Official figures put the big blip in retail figures down to motor vehicle sales, which jumped almost 30 per cent.

If these were excluded, the gloss would have been taken off the numbers: Overall sales would have dropped 0.8 per cent.

Most other sectors, in fact, registered declines, even traditionally stable ones like supermarkets.

But a few showed an uptick, including furniture and household equipment, computers and telecommunication apparatus and medical goods and toiletries.

The good news may not last long, however, as economists believe the retail market is softening.

Read the full story in Saturday's edition of The Straits Times.