Britain's FTSE 100 edged higher on Wednesday as tobacco stocks surged after U.S. Food and Drug Administration Commissioner Scott Gottlieb stepped down, while Just Eat dropped on the mid-cap index after releasing results.

The FTSE 100 was up 0.1 percent and the FTSE 250  was roughly flat by 0826 GMT.

British American Tobacco jumped 5.5 percent to a near four-month high and Imperial Brands rose 2.7 percent after U.S. FDA Commissioner Gottlieb, who strove to curb use of flavoured e-cigarettes, said he would step down next month.

DS Smith added 2.5 percent after an agreement to sell its plastics division to private equity firm Olympus Partners for an enterprise value of $585 million.

Dollar earners also provided some support as sterling came under pressure after talks between Prime Minister Theresa May's top lawyer and European Union negotiators over concessions on Brexit ended without an agreement. An EU official said the talks did not go well.

Luxury clothing company Burberry offset gains on the main bourse, falling 3.3 percent after Goldman Sachs downgraded the stock to "sell" from "neutral".

Life insurer Legal & General gave up more than 3 percent after its 2018 results, with Jefferies analysts flagging a "bulky margin miss".

Online takeaway service Just Eat dropped 3.4 percent on the mid-cap index despite posting higher 2018 results and forecasting improved margins for the current year.

"Questions remain over (Just Eat's) strategy and whether it needs to merge to protect its market position, whether the next CEO will have the expertise to drive growth in a tough sector, and just where... the current strategy focused on sales growth over profits (will) take the firm," said Markets.com analyst Neil Wilson.

Serviced office space provider IWG shed 2.8 percent after saying it would close or refurbish some locations in certain markets and posted annual results.

But defence contractor Ultra Electronics jumped 5.3 percent as it bulked up its order book.