* FTSE 100 down 0.5%, FTSE 250 down 0.4%
* Pub chain Ei Group up after buyout offer
* Investors wary as global trade war risks resurface
* ASOS sinks after latest profit alert
* Tobacco stocks up after Philip Morris results (Adds company news items, updates share moves)
By Shashwat Awasthi and Muvija M
July 18 (Reuters) - Britain's FTSE 100 followed other major stock markets lower on Thursday as initial batches of corporate earnings jangled nerves over global growth, while losses for London's mid-cap index were capped by a buyout of pub operator Ei Group.
All but two of the blue-chip index's sectors ended in the red as it shed 0.5% - its biggest intraday fall in nearly two weeks, while the mid-cap FTSE 250 lost 0.4%.
Among major drags on the main index were oil heavyweights Shell and BP, which tracked a slump in crude prices amid expectation that output would rise in the Gulf of Mexico following last week's hurricane, as well as miners .
Bright spots on the index were tobacco giants British American Tobacco and Imperial Brands after U.S. peer Philip Morris reported its sixth consecutive quarter of profit beat. BAT surged 6.1% on its best day in over a decade while Imperial Brands added 2.2%.
Slug and Lettuce owner Stonegate Pub Company <IPO-SPC.L> agreed to buy Ei Group for 285 pence a share, a 38% premium to Wednesday's close, which sent the mid-cap pub chain's stock to its highest in more than a decade.
The stock surged nearly 39% and helped fellow mid-cap pub operators Mitchells & Butlers, Greene King, J D Wetherspoon and Marston's rise between 1.3% and 4.2%.
TRADE WAR IMPACT
Meanwhile, the effects of a protracted China-U.S. trade dispute on corporate earnings and worries that trade tensions could further escalate have turned investors across the globe risk-averse.
Sentiment weakened as U.S. railroad operator CSX and German tech heavyweight SAP flagged an impact from the trade war and and a report https://on.wsj.com/2XNS9fB that progress towards a trade deal had stalled weighed on sentiment.
After a slump in May due to rising worries that Washington's trade war with China and other partners would escalate, the FTSE 100 has steadied and is on course for its best year since 2016.
The exporter-heavy index's gains have been fuelled by hopes of interest rate cuts by central banks and the plummeting value of the pound due to concerns around the Conservative leadership election and risks from Brexit.
AIM-listed ASOS tanked 23.2% to its lowest in 4-1/2 years after it blamed operational issues for its third profit warning in eight months.
Its shares also weathered their worst one-day drop since December, when the online fashion retailer's previous warning had triggered a global retail sell-off.
Luxury brand Burberry, which is on course for its best week in more than a decade after posting robust sales growth on Tuesday, gave up 1%.
Budget airline easyJet gained 3.4% on the midcap index after it stood by its annual profit forecast, reassuring investors despite softening demand in the industry due to Brexit-driven consumer uncertainty. (Reporting by Shashwat Awasthi in Bengaluru Editing by Patrick Graham and Arun Koyyur)