The FTSE 100 was down 0.4%, paring earlier heavier losses as sterling fell amid ongoing uncertainty over Brexit.
In the US a big earnings miss for conglomerate 3M saw futures markets point to a lower open on Wall Street later.
Elsewhere, the resignation of Royal Bank of Scotland chief executive Ross McEwan saw the bank's shares drop 2.4%.
LARGE AND MID CAP RISERS AND FALLERS
Barclays fell 2.7% as it reported a decline in first-quarter pre-tax profit amid a slip in total income owing to a challenging income environment for its corporate and investment bank division.
Sainsbury's slumped 4.4% after the Competition and Markets Authority's blocked the merger of Sainsbury's and Asda as Sainsbury's, Walmart and Asda 'mutually agreed' to terminate the proposed transaction.
Housebuilding company Taylor Wimpey dropped 3.2% even as it said the market for new-build housing had remained 'stable' in the first four months of 2019 despite ongoing political uncertainty, adding it was on track to meet its full-year expectations.
Investors appeared to be reacting to news of cost inflation and flat pricing which is expected to result in margin pressure.
Kaz Minerals slipped 1.5% despite saying it was on track to meet annual production guidance after reporting an uptick in copper output in the first quarter of the year amid record output at its Aktogay mine.
Oil company Tullow Oil fell 0.7% after it revised down its full-year production forecast following lower-than-expected first-quarter oil production due to now-resolved technical issues in its Ghana fields.
Anglo American shed 0.9% even as it kept its guidance on full-year production unchanged despite reporting a fall in first-quarter copper equivalent production, driven by slump in metallurgical coal production.
Housebuilder Galliford Try lost 2.3%, probably on a readacross from Taylor Wimpey, despite announcing it had been selected by Enfield Council to build the first 725 homes at the £6bn Meridian Water development in the Lea Valley.
Cobham edged 0.9% higher as it said first-quarter performance was in line with management's expectations and revealed that its cost-cutting programme in its advanced electronic solutions sector had commenced.
Acacia Mining dropped 4.3% after it swung to a loss in the first quarter of the year as revenue declined 12% amid lower sales and falling gold prices.
UK fertiliser development company Sirius Minerals climbed 3.8% after it announced it had entered into an exclusive 10-year supply and distribution agreement with European agribusiness group BayWa Agri Supply & Trade for distributing its POLY4 product in Europe.
UK chemicals business Synthomer lost 0.6% after it said that as trading in the first quarter had, overall, been in line with expectations, it had left its full-year outlook unchanged.
SMALL CAP RISERS AND FALLERS
Surveillance and security specialist Synetics fell 12.4% as it reported its annual results will be significantly more second-half weighted amid Brexit-related deferrals and delays to contracts.