The London market slipped in afternoon trading due to of the large number of firms that are trading ex-dividend.
The FTSE 100 Index fell 12.9 points to 6853.5, as heavyweights such as AstraZeneca, Barclays, Royal Dutch Shell and Lloyds Banking Group were all lower after declaring their next dividend payout will not go to new investors from today. The FTSE 250 Index rose 48.6 points to 17748.3.
IG senior market analyst Chris Beauchamp said the "ex-dividend bonanza has resulted in some big names falling sharply".
African-focused financial services firm Old Mutual blamed "challenging" markets as it posted lower profit in its first six months of the year, sending shares down 12p to 213.5p.
It said its pre-tax first-half operating profit fell 9% to £708m in the first half to the end of June compared to a year ago, as the firm was buffeted volatile currencies and lower than average market levels.
In the second tier, shares in Cineworld fell 5p to 588.5p, after Europe's largest cinema chain reported a sharp drop in interim profit on the back of currency headwinds.
In the six months to the end of June group posted a 34.6% year-on-year decline in pre-tax profit to £30.6m.
In afternoon trading the biggest risers on the FTSE 100 Index were Coca-Cola HBC (+117p to 1688p), TUI (+25p to 1037p), British American Tobacco (+91.5p to 4950p), Intertek Group (+63p to 3630p) and Imperial Brands (+68p to 4126p).
The biggest fallers on the FTSE 100 Index were Berkeley Group (-154p to 2459p), Old Mutual (-12p to 213.5p), Direct Line (-18.6p to 374.4p), BT Group (-15.8p to392.7p) and British Land (-18p to646p).
In afternoon trading the biggest risers on the FTSE 250 Index were DFS Furniture (+32.7p to 256.7p), Hastings Group (+8.6p to 214.7p), Tullett Prebon (+12.1p to 361.6p), Ascential (+8.3p to 248.4p) and G4S (+7.8p to 235p).
The biggest risers on the FTSE 250 Index were Card Factory (-23.3p to 297p), Aldermore Group (-10.4p to 143.2p), Derwent London (-92p to 2727p), Countrywide (-6.2p to 232.2p) and Man Group (-2.9p to 113.4p).