* FTSE 100 down 0.9 pct
* FTSE 250 UP 0.1 pct
* Centrica drops after weak outlook
* BAE, exporters, miners also drag main index lower
* Purplebricks tanks on revenue cut (Adds company news item, analyst quote, updates to closing prices)
Feb 21 (Reuters) - British blue-chip shares fell on Thursday after downbeat reports from energy supplier Centrica and defence company BAE Systems, while a stronger pound dragged on multinational companies and miners also weighed.
Purplebricks was a major loser as the online estate agent shed nearly a quarter of its value after cutting its revenue target.
The FTSE 100 was down 0.9 percent, while strength in sterling helped the domestically-focussed FTSE 250 add 0.1 percent.
British Gas-owner Centrica hit a near 16-year low and dropped 11.7 percent after warning that a national price cap on energy bills would hit its 2019 results.
BAE Systems fell 7.9 percent on its worst day in five years. It said German moves to block exports to Saudi Arabia could hurt its deals with Riyadh and weigh on its financial performance.
Tobacco company Imperial Brands shed 4.1 percent as the stock traded ex-dividend. In addition, CMC Markets analyst David Madden said a risk-on attitude among investors was leading them to dump defensive stocks such as tobacco.
Sterling rose after British finance minister Philip Hammond said talks with Brussels had been constructive and parliament might vote on a revised Brexit deal as early as next week.
Copper prices retreated from multi-month highs, leading miners to their worst day in seven weeks and further pressuring the main index.
"There doesn't appear to have been one particular catalyst (for FTSE's fall), however weak manufacturing reports from Japan, France and Germany suggest that the global manufacturing sector is heading towards a possible recession," said CMC Markets analyst Michael Hewson.
Information and analytics provider Relx outperformed the index and rose 4.8 percent on a bullish view for 2019.
AIM-listed Purplebricks plummeted nearly 25 percent on its worst day ever after it cut its full-year revenue forecast and said the chief executives of its British and U.S. units would leave.
Georgia's biggest retail bank TBC Bank Group climbed 9.5 percent to the top of the mid-cap index as its full-year earnings surged and it took action to resolve a dispute with the country's central bank over its corporate bank subsidiary.
Gambling software developer Playtech jumped 8.2 percent after announcing a share buyback and guiding for higher core earnings in2019.
However, recruiter Hays skidded 4.2 percent to the bottom of the mid-cap index as it warned that growth would be curbed by lower contractor extensions in Germany, its biggest market.
Just Eat slid 4.8 percent after a Financial Times report that Uber would cut fees for food delivery in UK and Ireland.
(Reporting by Shashwat Awasthi and Muvija M in Bengaluru; Editing by Larry King, William Maclean)