The FTSE 100 Index fell 28.90 points, or 0.5%, to 5,652 points today, led by miners.
Miners gave up their earlier gains after a report by the International Copper Study Group showed world supply exceeded demand in the first quarter of the year.
Anglo American dropped 2.01% to 2,095p, Rio Tinto fell 2.14% to 2,750p and Kazakhmys declined 1.44% to 1,093p.
Gallaher fell back 1.39% to 816p after it said trading remains in line with expectations.
The news led tobacco rival British American Tobacco down 1.91% to 1,332p.
Other defensives also fell back, with United Utilities down 1.44% to 651.50p and Severn Trent down 0.93% to 1,172p.
Smith & Nephew fell 1.51% to 408.25p on fears it could be drawn back into the current US probe into the world's major orthopaedics companies.
Meanwhile, broker comment was the main driver for those with the biggest gains with Reckitt Benckiser up 0.42% to 1,930p as SG kept its 'buy' advice and 2,400p price target, arguing the group is set to reap rewards from its recent BHI acquisition.
In the US, the Dow Jones industrial average is little changed, up 10.09 points, or 0.09%, at 11,055.37 points, ahead of a Federal Reserve statement on Thursday which is expected to shed light on the outlook for interest rates.
A flurry of deal activity is offering support and shares of Univision have jumped 7% to $34.19 after the company accepted a $12.4bn takeover offer.
A rise in crude oil prices has lifted energy stocks, with shares of Exxon Mobil up 1.4% to $59.64.
Palm has risen 3.3% to $18.69 after RBC Capital Markets upgraded it to "outperform".
Shares of DuPont are the biggest drag on the Dow, down 2.6% at $40.97, after French telecoms and media group Vivendi said it sold its 1.8% stake in the chemical company.IFAonline
Two global vehicles
'Further plug advice gap'
Must appoint separate CEOs and boards
Advisers do come out well
Will report to Mark Till