A volatile day on the UK market saw the FTSE 100 index lose some of the ground gained earlier in the week.

With military action continuing in Afghanistan and the FBI warning of the potential for further terrorist attacks over the weekend, it was always going to be difficult for the London market to make further progress.

The FTSE 100 index had a volatile opening, with the high for the day of 5,187.5 and the low of 5,081.2 (down 83.7) occurring within 90 minutes of each other.

After some good news from Juniper Networks late on Thursday, a profit warning from Cap Gemini Ernst & Young weighed on sentiment.

Another bout of volatility occurred in the afternoon on the back of some mixed US economic news. US retail sales figures for September were much weaker than expected, dropping 2.4 per cent on the month in the wake of the terrorist attacks on New York and Washington. That pushed the US futures market lower and sent the FTSE 100 index back down to 5,100.

When Wall Street opened, the Dow Jones Industrial Average, which recorded triple-digit gains on both Wednesday and Thursday, quickly notched up a triple-digit loss.

But the Dow stabilised with the help of the University of Michigan's consumer sentiment index, which rose to 83.4, rather than falling as expected. That figure, running counter to the tenor of the retail sales data, created a rather confused picture of the health of the US economy.

The FTSE 250 rose 46.8 to 5,450.9, the SmallCap 17.3 to 2,306.5 and the Techmark 100 5.41 to 1,333.13.

Over the week, the FTSE 100 gained 2.2 per cent, the 250 gained 4.1 per cent, the SmallCap 5.2 per cent and the Techmark 100 9.1 per cent.

There was a bit of a rebound in defensive stocks yesterday with utilities performing well, while some of the stocks that rebounded earlier in the week, such as Sage and Daily Mail, dropped back.

Turnover was 2.41 billion shares by the 6 p.m. point, with more than 200 million dealt in Marconi. More than 136,000 individual trades were conducted.