A FIGHTBACK by London's FTSE 100 Index was not enough to haul top flight shares into positive territory as worries over the weakness of the US dollar hammered stock markets around the world.

After enduring a bumpy ride for much of the day, the benchmark Footsie lost sight of a lunchtime improvement to end the day 6.5 points lower at 4221.7.

Blue chip shares tested the psychologically important 4200 mark earlier in the session having lost almost 30 points on Monday, but by the close the mood in London had recovered.

The mood was not aided by a slow start on Wall Street, which saw the Dow Jones Industrial Average dip and the tech-laden Nasdaq hold steady as fears continued over the weak dollar.

The biggest riser on the FTSE 100 was broadcaster BSkyB, which climbed 17p to 639p as the company allayed fears in the City that it was about to parachute Rupert Murdoch's son, James, into the chief executive's position.

Following the announcement of Tony Ball's departure, BSkyB said its independent directors would meet to recommend a successor.

But in a mixed session for media stocks, magazines and radio group Emap headed the fallers board, shedding 36p to 821p despite forecasting a three per cent rise in revenues for the six months to September 30.

Investors, however, appeared more concerned about the company's cautious outlook, with Emap reporting that it was still too early to call the start of a major upturn in the advertising market.

And global information provider Reuters climbed a penny to 237p after unveiling plans to relocate most of its London staff to a single site in Canary Wharf, in a move expected to save £5m a year.

Insurer Royal & Sun Alliance recovered from a severe drop earlier in the session to finish the day 1p higher at 93p as investors digested the impact of a rights issue, which was approved by shareholders yesterday.

Also doing well were mobile phone rivals mmO2 and Vodafone which each rose a penny to 59p and 124p respectively.

On the downside, plant hire business Wolseley surrendered much of its early gains after announcing record annual profits of £455.9m despite "mixed" economic conditions in the US and mainland Europe. Shares, which had been 8p ahead in the first hour, ended 2p weaker at 714p.

Outside the top flight, computer games retailer Game rose 2p to 62.