The FTSE 100 Index fell 23 points, or 0.4%, to 6,208 points today, led by drug companies GlaxoSmithKline and AstraZeneca.
GlaxoSmithKline declined 1.88% to £13.60 and AstraZeneca fell 2.11% to £30.10 on fears the US Congress will cut the price of drugs following Democrats triumph in the recent mid-term elections.
The miners presented a mixed picture, as BHP Billiton fell 2.59% to £10.16 and Xstrata dropped 2.51% to £22.95, while Lonmin jumped 3.04% to £31.83 on the back of bid rumours.
Anglo American rose 1.22% to £24.96 after the Oppenheimer family sold a third of its stake in the world's second-biggest miner to China Vision Resources. The transaction is worth around £419m.
In the US, the Dow Jones industrial average is up 15.53 points, or 0.13%, at 12,118.83 points, as worries about the sustainability of Walt Disney's earnings growth offset a jump in shares of American International Group.
AIG shares have risen 2.4% to $69.66, a day after the world's largest insurer by market value said quarterly profit more than doubled, benefiting from an absence of major hurricanes hitting the United States this year.
A pullback in oil prices is helping shares of industrial companies such as diversified manufacturer Honeywell International, whose stock has risen 0.3% to $42.34.
Boeing has gained 1.76% to $86.61 after the plane maker won a US Air Force helicopter contract valued at $15bn through 2019.
But shares of Disney have dropped 3.5% to $32.40 after it posted a stronger-than-expected quarterly profit but raised concerns about sustainability of earnings growth in the months ahead.IFAonline
According to Cicero report
Adds 24 staff, three offices and £275m AUA
Launches Junior ISA and retirement accounts
Schroders tops 2019 list
24 companies wound up