Advertising giant WPP led the London stock market lower after it gave a cautious outlook for the year ahead.
WPP shares fell 6% after it said 2017 had got off to a slow start, citing "continued tepid economic growth".
The comments overshadowed news of record annual revenues of £14.4bn, which were helped by last year's fall in the value of sterling.
WPP was the biggest faller in the FTSE 100, with the benchmark index down 24.08 points at 7,358.27.
In the FTSE 250, shares in WH Smith rose 5.3% after Barclays upgraded its rating for the retailer to "overweight" from "equal weight".
On the currency markets, the pound fell 0.1% against the US dollar to $1.2254 and dropped 0.2% against the euro to 1.1650 euros.