Britain's FTSE retreats, though robust results boost Barclays

(ADVISORY- Follow European and UK stock markets in real time on the Reuters Live Markets blog on Eikon, see cpurl://apps.cp./cms/?pageId=livemarkets)

* FTSE 100 down 0.2 pct

* Barlcays top gainer after results

* Though Amec Foster Wheeler, Berendsen (LSE: BRSN.L - news) weigh on midcaps

By Kit Rees

LONDON, Oct (HKSE: 3366-OL.HK - news) 27 (Reuters) - British shares fell on Thursday in a choppy session as earnings updates weighed on midcaps, though Barclays (LSE: BARC.L - news) rose on a robust set of third-quarter results.

The blue-chip FTSE 100 index was down 0.2 percent at 6,941.99 points by 0917 GMT, while the more domestically-focused FTSE 25 slipped 0.9 percent.

The FTSE 100 retreated after upbeat UK GDP data showed that Britain's economy was resilient in the period following the UK referendum to leave the European Union, prompting a rise in sterling and sending UK bond yields to a post-Brexit high.

"A stronger-than-expected GDP figure from the UK ... does fuel the story that the Bank of England won't have to act any time soon to actually prop up the economy, because it seems to be doing fairly well," Jonathan Roy, advisory investment manager at Charles Hanover Investments, said.

"If we see a strengthening in the pound, that's likely to take the shine off some of these multinational companies that have rallied on expectations of higher profits on a weaker pound."

Barclays, however, was the top riser on FTSE 100, up 1.7 percent after its third quarter results beat forecasts.

The lender posted a rise in third quarter profits to 1.7 billion pounds ($2.08 billion), helped by an improvement in its investment banking division.

"Barclays still has work to do, but there's an increasing amount of light at the end of the tunnel," Laith Khalaf, senior analyst at Hargreaves Lansdown (LSE: HL.L - news) , said in a note.

"However despite the bank's international exposure, it is still vulnerable to poor economic conditions in the UK, so if we do get a Brexit-induced slowdown, Barclays will feel the burn."

Barratt Developments (Frankfurt: 859551 - news) fell more than 6 percent after trading ex-dividend, while BT dropped 3.4 percent after its own update.

The British midcaps underperformed their blue-chip peers after disappointing results weighed on shares in Amec Foster Wheeler and Berendsen.

Oil services firm Amec Foster Wheeler (Other OTC: AMCBF - news) slumped more than 18 percent, heading for its worst day in almost a year after cancelling its capital markets day and posting weak sales figures.

Commercial laundry company Berendsen tumbled nearly 17 percent on a profit warning.

This follows profit warnings from fellow midcaps Cobham (Amsterdam: CH6.AS - news) , Keller and Senior (Other OTC: SNIRF - news) over the past week.

"This earnings season isn't shaping up to be particularly great for medium-cap companies. They are the ones that are feeling the pinch of Brexit that's been demonstrated in recent sets of earnings," Charles Hanover Investments' Roy said. (Reporting by Kit Rees; Editing by Andrew Heavens)