(Reuters) - Poor results from tour operator TUI dragged Britain's FTSE 100 down on Thursday as advertising group WPP also weighed on the main index.
The FTSE 100 was down 0.2 percent by 0838 GMT. The domestically-focused FTSE 250 was 0.6 percent lower, ahead of a Bank of England meeting and Prime Minister Theresa May's visit to Brussels to seek changes to a Brexit deal.
London-listed shares of TUI AG slumped 18 percent to their lowest in nearly two years after the tour operator slashed its earnings forecast for the fiscal year, blaming warm weather and weakness in the pound.
Advertising agency WPP tumbled 6.9 percent after French rival Publicis reported negative revenue growth for the fourth quarter - far weaker than the market expected.
But Compass Group outperformed the main bourse as the world's biggest catering firm rose 3.7 percent after posting higher first-quarter organic revenue and providing bullish full-year forecast.
The FTSE 250 also saw steep fallers.
Pork and poultry producer Cranswick plunged 21 percent, on track for its worst day in more than 11 years after quarterly results.
Oil firm Petrofac lost 13 percent after a former executive pleaded guilty to bribery as part of an ongoing Serious Fraud Office investigation.
On the small-caps, Thomas Cook jumped 7.4 percent, reversing early losses, after it put its airline business up for sale to raise cash and help steady operations after a rough 2018.
(Reporting by Shashwat Awasthi and Muvija M in Bengaluru; editing by Helen Reid)