Comments from Federal Reserve chief Jerome Powell suggesting a rate cut could be on the way briefly boosted investor sentiment.
However, by the close the FTSE 100 had given up initial gains to trade down 5.78 points at 7,530.69.
In the US the S&P 500 was up 0.3% at 2,988.15 by 4.30pm UK time having earlier broken through the 3,000 mark for the first time in its history.
Shares in software firm Micro Focus fell 11.5% as the company was hit by negative broker comment in the wake of yesterday's trading update.
LARGE AND MID CAP RISERS AND FALLERS
Fashion retailer Superdry dropped 3.1% after it swung to a full-year loss and slashed its dividend, while warning that its sales would fall in the current financial year.
Homebuilder Barratt Developments was up 1.4% after announcing that it expected pre-tax profits to be ahead of market expectations, amid a strong close to the year and additional contribution from joint ventures.
Homewares retailer Dunelm fell 1.8% as it grew like-for-like revenue in the fourth quarter by 15% while also expanding its margins.
Pub chain JD Wetherspoon gained 3% on the back of a 6.9% rise in like-for-like sales during the fourth quarter of its financial year.
Recruitment company Page slumped 14.5% after it guided for its full-year result to come in at the bottom end of market expectations, amid falling profits in the UK.
SMALL CAP RISERS AND FALLERS
Small cap RedX Pharma gained 100% as it announced the $203m sale of its pre-clinical cancer programme.
Bowling alley operator Ten Entertainment climbed 3.4% after it grew its sales by 9.6% in the first half, as cooler weather helped boost footfall.
Communications services provider to businesses Gamma Communications advanced 2% on announcing that its full-year earnings were on track to be 'slightly above' the range of market expectations.