FTSE snaps winning streak as Shell, AstraZeneca miss forecasts

* FTSE 100 off 0.4 percent

* Shell (LSE: RDSB.L - news) , AstraZeneca (NYSE: AZN - news) weigh on index post results

* Sentiment hurt by less dovish than expected Fed

By Tricia Wright

LONDON, Oct (KOSDAQ: 039200.KQ - news) 31 (Reuters) - Britain's top shares fell on Thursday, as firms including Royal Dutch Shell (Xetra: R6C2.DE - news) and AstraZeneca (Dusseldorf: ZEG.DU - news) posted weak results and after comments from the U.S. Federal Reserve suggested it was less alarmed about the economy than some had anticipated.

Oil major Royal Dutch Shell dropped 4.6 percent, while drugmaker AstraZeneca shed 2.6 percent after third-quarter results from the pair undershot analysts' forecasts.

Royal Dutch Shell - A and B shares - and AstraZeneca were the biggest individual drags on the UK benchmark, weighing on the index to the tune of 28 points.

Of the 43 percent of European companies that have announced results so far, 50 percent have missed earnings expectations, according to Thomson Reuters Starmine data.

However, on the revenue front, 68 percent of companies have missed forecasts, which could lead to a squeeze on margins and pressure on future earnings.

Further dampening sentiment, the Fed, as was widely expected, kept its $85 billion-a-month stimulus plan intact, and made little change to the accompanying statement from the one in September. But traders said it was less dovish than it might have been in light of recent downbeat economic data.

Some investors, however, remained bullish on the UK benchmark, currently trading just shy of five-month highs, seeing any weakness as a buying opportunity.

"The FTSE might be under a bit of pressure after it has become clear that the Fed will taper as soon as economic data improves but until that is in fact the case people will most likely continue to buy the dips," said Lex van Dam, hedge fund manager at Hampstead Capital.

The UK blue chip index was down 26.27 points, or 0.4 percent, at 6,751.43 points by 0835 GMT, having closed up 2.97 points on Wednesday, flat in percentage terms, to eke out its fifth successive day of gains.

The FTSE 100 has risen 4.5 percent so far this month, helped by expectations of continued U.S. monetary stimulus alongside relief over a political deal to avert a U.S. sovereign default.

But technical analysts say it does look ripe for a pull-back, with its 14-day relative strength index (RSI), a momentum indicator, having run up to 72.6 in the previous session, a five-month high, with a reading of 70 and above considered to be 'overbought'.

"Anyone looking for a reason to sell is perhaps using that as an excuse. But any further weakness from here is going to start looking like a failure at resistance," Charles Stanley (LSE: CAY.L - news) , technical analyst Bill McNamara said, referring to the fact that the index rose to within touching distance of its year high, at 6,875, on Wednesday, and could struggle to overcome this. (Reporting by Tricia Wright, editing by Elizabeth Piper)