The FTSE 100 closed down 0.97 per cent at the end of another volatile week.

The index closed at 4,149.64 on a day that defined the week as a whole – seeing a series of gains and losses.

Over the week the index increased 2.40 per cent – after oscillating steadily for five days.

Today, it was the miners that turned the index downwards – with Xstrata down 11.77 per cent, BHP Billiton falling 7.45 per cent, Eurasian falling 6.35 per cent and Antofagasta dropping 6.10 per cent.

British Airways fell 8.94 per cent.

Leading the gains was Land Securities – up 8.84 per cent – followed by 3i Group rising 7.84 per cent and Barclays up 5.78 per cent.

Leading the focus was US GDP figures – which revealed the final quarter of 2008 recorded a 3.8 per cent fall in economic output, the worst in over 26 years.

The Dow Jones responded to the figures by dropping 1.13 per cent to 8,057.01 by 12:36 EST (17:36 GMT).

Anthony Grech, market strategist at IG Index, said: “In the end, the US GDP figures showed the American economy slowing at its fastest rate since the 1980s – but this number was still not as bad as the market was expecting.

“However any respite for shares was short lived again due to US numbers.

“Disappointing updates from the likes of Procter and Gamble and Caterpillar managed to erase any positive sentiment and the sell off in the US pushed the FTSE back to the 4100 mark.”

He added: “Against this pessimistic backdrop, it is difficult to see what catalyst there is going to be in the short term to give stock markets any sort of meaningful boost.

“It looks like investors are going to have to content themselves with the odd brief rally and remain vigilant to the real risks. As the economy continues to worsen, there could well be more of the bear market still to come.”