Poor news from overseas technology companies has hit the FTSE-100 Index, which has lost 47.8 points.
It now stands at 5632.6 after the German chip maker Infineon Technologies issued a profit warning and US telecom equipment maker put out a downbeat trading statement.
Major casualties include Marconi, which has plunged 18p to 248p, while fellow equipment firm Spirent has dived 13¼p to 176¼p and Energis has shed 13½p to 190p.
Cable & Wireless is down 20½p at 383½p and Vodafone is off 4½p at 157p.
But Colt Telecom has fallen most, diving nearly 11%, or 57½p, to 492½p.
Arm has been hard hit by the Infineon warning, sliding 9% - off 24p at 237½p.
Logica, Dimension Data and CMG are all lower - off 34p at 818p, 9p at 286½p and 13¼p at 312¼p respectively.
Software groups were also hit, with Misys sliding 32p to 435p and Sage falling 6p at 239½p.
With investors pulling out of tech stocks, old economy shares such as retailers have gained.
Dixons is up 5½p at 216½p, Boots is up 11p at 576p and Marks & Spencer has risen 1½p to 238½p.
Rolls Royce is also up 3½p at 234p after announcing two big orders from American customers today.