The main stock market index <.FTSE> inched lower by 0.2%, but still outperformed its U.S. and European counterparts, while the mid-cap FTSE 250 <.FTMC> was up 0.2% with gains led by aerospace firm Cobham that surged after a buyout offer.

Diageo slumped 3.4% after its capital return plans were less than what some analysts had expected, though the company reported higher annual profit helped by the popularity of its "Game of Thrones" inspired scotch.

Software firm Sage and information and analytics provider Relx slumped 10.4% and 3.7%, respectively, after downbeat updates, while consumer goods giant Unilever fell as rainy weather hit ice cream sales in Europe and North America.

Helping contain the losses was AstraZeneca, which jumped nearly 8% to an all-time high after raising its annual product sales forecast, as cancer drugs helped its second-quarter results beat analysts' estimates.

Market sentiment broadly weakened after the European Central Bank meeting, in which ECB President Mario Draghi all but pledged to ease policy further as the growth outlook deteriorates, and said that there was no discussion of a rate cut.

"Draghi indicated they didn't really even discuss a cut today so that's what surprised the market and that's why we're seeing this reversal, but it doesn’t change the bigger picture," said Jeremy Gatto, investment manager at Cross Assets Solutions team in Unigestion.

Among midcaps, Cobham soared 34.5% to 165.8 pence, roughly matching the 165 pence per share offered by U.S. private equity group Advent International that valued the London-listed company at $5 billion.

"It's the latest sign that more firms are happy to go private and take them out of the glare of public markets," Wilson said. "It's also a sign that weakness in sterling continues to make UK companies attractive to foreign buyers."

However, gains on the FTSE 250 were kept in check by Metro Bank, which plunged more than 19% to an all-time low after it disclosed that customers had pulled 2 billion pounds out this year following an accounting error and said its founder would stand down as chairman.

Shares of Aston Martin, which shed over a quarter of their value after the luxury carmaker cut its 2019 volumes forecast in the previous session, fell another 18%, deepening its losses for the year to 47%.

(Reporting by Shashwat Awasthi and Muvija M in Bengaluru; Editing by Shounak Dasgupta and Frances Kerry)

By Shashwat Awasthi and Muvija M