Technology firms face an uncertain business climate following the attacks on the World Trade Centre and the Pentagon and may have to issue a spate of profit warnings, analysts warned yesterday.

But the long-term impact on the high-tech sector is still unclear and may not be known for many months. Mr John Coolican, technology analyst with Merrion Stockbrokers, said software and hardware firms would be affected by the timing of the terrorist incident. Coming just two weeks before the end of the quarter, vendors may not be able to gain access to executives to clinch deals, he said. "These companies typically sell a large percentage of their quarterly sales in the third month of a quarter,"' he said. "Iona sells about 50 per cent of its business in the third month of a quarter."

According to Mr Gerry Hennigan, analyst with Goodbody Stockbrokers, the consequences for technology firms rest on the general economic situation.

"The US economy was at a fairly fragile state already," he said. "If consumer spending slows, it will drip down to businesses eventually."

But Mr William Malik, vice-president area research at the US consultancy Gartner, was more upbeat on the sector, arguing that it may promote broad shifts in work patterns. "We'll see more people working from home and using technology," he said. "People may then upgrade their computer equipment."

Mr Sami Pokjolainen, research manager at consultancy IDC, said it would also create new sales opportunities for hardware firms as companies were forced to replace equipment. Although the Nasdaq slipped more than 7 per cent yesterday, some technology sectors, including defence and security, proved resilient to the threat of a downturn.