THE FTSE edged up on opening but investors remained jittery ahead of a key Fed meeting on Friday and a string of company results - particularly in the beverage industry - which showed weak consumer demand.
US Federal Reserve Chairman Ben Bernanke is set to make a key speech at an annual central bank conference in Jackson Hole, where it is expected he will provide hints for further measures to revive the struggling economy.
But investors and traders remained uncertain over whether such a move would be effective.
The cutting of Japan's credit rating by one notch by Moody's also cast a shadow although the FTSE held steady amid general European weakness.
The world's largest hedge fund manager Man Group was the biggest climber on the FTSE 100, up 3.4 per cent.
Tullow Oil jumped by 3.2 per cent after reporting strong first half results and revealing that an exploration deal in Uganda would be completed by September.
Advertising giant WPP was also up more than three per cent after a trading update showing that it was hitting forecasts.
RBS was the fastest climber among the major banks, up two per cent. All the others dipped. Cairn Energy also edged up by just over one per cent to be among the top five best performing stocks in early trading.
Insurer Admiral was the biggest faller on London's blue chip index, down more than seven per cent despite reporting a rise in profit and revenue in excess of £1bn. Analysts said a deeper look at the profit figures raised questions.
Other fallers included drinks giant Diageo, down more than two per cent. It announced that it had completed the acquisition of Turkish drinks company Mey Içki.
SABMiller fell by 1.8 per cent as the uncertainty over its bid for Foster's seemed to take its toll.
Across Europe brewer Heineken dived by 15 per cent after issuing a warning over tough trading conditions.