The FTSE 100 index closed up 145 points at 6,185 on Thursday as UK technology and telecom stocks benefited from Wednesday's cut in US interest rates. Colt Telecom (quote: CTM) showed the biggest percentage gain, and was up 18 percent at the close. Mobile network operator Vodafone (quote: VOD) also had a good day, gaining almost seven percent on the back of positive mobile phone sales figures for the last quarter of 2000. Other companies in the telecoms sector did well. BT (quote: BT) was up nearly ten percent, Cable & Wireless (quote: CW) added nine percent to its value, and Marconi closed up eight percent. The Techmark, London's index of technology companies, recorded a gain of 4.5 percent -- up 115 points at 2,459. High-tech stocks Sage Group (quote: SGE) and Misys (quote: MSY) both closed up more than 12 percent. US markets opened cautiously, however. As the London stock market closed the Dow Jones was only 29 points up after two hours trading, while the Nasdaq Composite -- America's technology index -- had shown little change. However, Thursday's bounce does not disguise the inevitable, according to financial observer Simon Moores, chairman of The Research Group. "Obviously people are encouraged by what's been happening in the States," he says. "But come what may, the US looks like it is moving into a slowing down of its economy." Moores also says that, although the UK economy is comparatively healthy, this is unlikely to save many dot-com firms, which will be looking for a second round of investment in April and May. "I think April will see some high-profile failures," he says. For complete business coverage, see ZDNet UK's Enterprise Channel. See techTrader for the latest technology investment news, plus quotes and research. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet News forum. Let the editors know what you think in the Mailroom. And read other letters.