* FTSE 100, mid-caps up 0.5 pct
* Barclays drops after Q3 results, IB division weak
* Glaxo hit again in results fallout
* Shire falls on Celgene warning read-across
* Commodities stocks, staples support index (Udpates prices, adds detail)
By Kit Rees and Helen Reid
LONDON, Oct 26 (Reuters) - Strong commodities stocks and a weaker pound helped Britain’s top share index recover from three-week lows on Thursday, though Barclays fell sharply after its third quarter update.
The FTSE 100 closed up 0.5 percent, its best day in a week as dollar-earning stocks got a boost from a falling pound after the worst plunge in retail sales since 2008.
British stocks did not however fully join in the strong rally among European equities, boosted by a weaker euro after the European Central Bank committed to extending asset purchases until at least September 2018.
Barclays was the standout faller, its shares down 7.4 percent to their lowest in a year, after the bank missed estimates for third-quarter profit on the back of weak trading performance at its investment banking division.
Barclays has been the worst-performing bank on the FTSE 100 this year, down 18.6 percent year-to-date.
Barclays’ results contrasted with Lloyds’, whose shares ended Wednesday’s session with a slight gain despite an initial wobble.
“The main thing (with Barclays) is there’s been a big drop in the income from the investment bank, which is more of a market-wide issue ... and probably a bit of sideways movement in the rest of the business,” Laith Khalaf, senior analyst at Hargreaves Lansdown, said.
“It’s a bit of a damp squib of a set of results.”
GlaxoSmithKline shares fell 3.4 percent, extending Wednesday’s post-results losses to hit their lowest since the Brexit vote aftermath, after Credit Suisse cut its target price on the pharma stock.
Analysts at the Swiss bank pointed to uncertainty over Glaxo’s HIV segment ViiV and said the company’s post-results call was more cautious than expected.
Healthcare firm Shire fell 2.1 percent despite earlier receiving European approval for its drug Firazyr to be extended to paediatric patients.
Shore Capital analysts put the drop down to a profit warning from U.S. biotech company Celgene.
“Celgene has been a bellwether for the sector,” said ShoreCap analyst Tara Raveendran.
Among mid and small-caps, Spire Health shares also fell 3.2 percent and Biotech Growth Trust dropped 4 percent.
Analytics and information firm RELX meanwhile gained 3 percent after a trading update analysts said was in line with expectations.
Foreign-earning consumer goods stocks British American Tobacco and Unilever added the most points to the index, while miners Rio Tinto, Anglo American and BHP Billiton also supported.
Galliford Try and Barratt Development shares fell as they went ex-dividend.
So far the British third-quarter results season has been marred by significant share price drops from large-cap firms such as Convatec and Whitbread, as well as profit warnings from small-caps Pendragon and Dialight earlier in the week.
“If you look at UK domestic firms, there’s quite a lot of bad news that’s expected because Brexit is hanging over results,” Hargeaves Lansdown’s Khalaf said.
Estimates from Morgan Stanley show earnings are expected to grow by more than 20 percent in the United Kingdom in 2017, against 12.6 percent growth for MSCI Europe.
A high proportion of Britain’s earnings growth is driven by the heavyweight energy sector, however, and is also helped by a weaker pound.
Morgan Stanley expects British earnings growth to weaken in 2018 and 2019.
Reporting by Kit Rees and Helen Reid; editing by Peter Graff