Disappointment at the latest results from telecoms giant Vodafone helped put an end to a five-day winning streak by the FTSE 100 Index.
The world's biggest mobile phone operator stressed concerns about growth in areas such as Asia, taking the shine off news of a large share buyback programme and full-year earnings that beat market expectations.
The stock headed the Footsie fallers with a drop of nearly five per cent, or 7p to 139.5p, and contributed to the index closing 7.3 points lower at 4982.5.
The swing in sentiment also affected rival Cable & Wireless, off 3.25p to 128.5p, and O2, which shed 2.25p to 124.5p, after a strong run since its full-year results last week.
Negative momentum from across the Atlantic was also bearing on the Footsie, with the Dow Jones 30 points lower by the close in London.
On a busy day for corporate news, Scottish Power was among those trying to improve the mood.
The stock added six per cent, up 27.75p to 469.75p, after announcing the sale of its US arm PacifiCorp for $9.4 billion, with nearly half that being returned to shareholders.
Major rival International Power added 3.75p to 188p.
Publishing group Emap was second in the top flight risers after reporting a good start to the year despite a 41 per cent decline in profits and tough trading in France.
Shares lifted 30p to 795p. Marks & Spencer also featured on the Footsie risers' board despite announcing a 19 per cent drop in underlying full year profits and a challenging outlook.
Shares gained 5.25p to 342.25p as investors expressed relief that M&S did not warn on profits.
Miners were doing well as one broker talked up Xstrata's trading prospects and rumours continued to circulate about a bid to counter BHP Billiton's offer for Australian group WMC. Shares in BHP jumped 14p to 652p while RioTinto was up 28p at 1632p and Xstrata lifted 16p to 976p.
Outside the top flight, budget airline easyJet weakened four per cent, or 10p to 238p, after it said high oil prices would leave its full-year profits below the level of last year.
Fashion house Burberry was in the red, losing 6p to 379p, after announcing 17 per cent rise in annual profits to £164.4 million but reporting "muted" demand in some of its markets.
The highest Footsie risers were: Scottish Power up 27.75p to 469.75p, EMAP adding 30p to 795p, Alliance Unichem up 18p to 827.5p and Antofagasta rising 24p to 1112p.
The heaviest fallers were: Vodafone down 7p to 139.5p, Cable & Wireless losing 3.25p to 128.5p, O2 down 2.25p to 124.5p and Man Group off 19p to 1213p.