New figures showing US oil inventories have grown in recent weeks helped push the price of crude oil down today, with the result UK oil majors Shell and BP also fell, pushing the FTSE 100 index down 15.30 points to 4,489.50.
Boots dropped most, shedding 20p to 650p as its shares went ex-dividend.
BP dropped 11.5p to 480.75p and Shell fell 5.25p to 395p.
Rio Tinto dropped 24p to 1,295p to lead the mining sector down after analysts at BMO Nesbitt Burns downgraded the company.
BSkyB jumped 17p to 629p after announcing plans to offer free access to its digital satellite television broadcasting to better compete with the terrestrial digital service Freeview.
BT added 2p to 187.5p after announcing it is to switch its entire residential telephone network to an internet-based system, which will save an estimated £1bn annually in costs.
The FTSE 250 index climbed 14.3 points to 6,162.4.
Colt Telecom added 2.5p to 88p on speculation France Telecom may bid for the provider of corporate telecoms services.
Shares dropped across much of Europe today, and markets in New York are following suit.
The Dow Jones Industrial Average index is down about 43 points to 10,389, while the broader S&P 500 index is off by about 7 points to 1,134.
Investors there have switched focus from energy prices to corporate earnings potential against share prices, which have rallied in recent weeks.IFAonline
To promote 'long-term investment'
Switching 'hard and expensive'
Smaller funds still packing a punch
To drive progress