* FTSE 100 falls 0.5 percent in second day of losses
* Economic growth concerns weigh ahead of earnings season
* Technical charts still open to further gains
By Toni Vorobyova
LONDON, Oct 9 (Reuters) - UK shares fell for a second session on Tuesday, dented by a wary view of Europe's debt troubles and concerns that gloomy global economic data bodes ill for the upcoming corporate earnings season.
UK data showed manufacturing output shrank more than expected in August and exports fell steeply, pointing to deterioration both in the domestic and the global economy.
The International Monetary Fund forecast that the UK economy would contract 0.4 percent this year versus growth of 0.2 percent expected in July, and combined this with a more downbeat view on global growth.
That backdrop exacerbated concerns about the third quarter earnings season, which kicks off with U.S. aluminium giant Alcoa
after the market close, along with fast food restaurant operator Yum Brands .
"People are getting cautious about the earnings season. I am quite bearish," said Nick Xanders, who heads European equity strategy at broker BTIG.
"Tonight is going to tell you exactly which way we are going ... Alcoa will tell you what's going in terms of UK miners. Yum will be very interesting to see in terms of Chinese growth."
The FTSE 100 closed down 31.49 points, or 0.5 percent, at 5,810.25 points , adding to a 0.5 percent drop the previous session.
Concerns about the euro zone remained in the spotlight, with Spanish bond yields edging higher as the country continued to drag its feet over a formal bailout request needed to kick-start a European Central Bank plan to ease the crisis through sovereign bond purchases.
After jumping some 700 points between early June and mid-September, the UK benchmark has stalled, trading in a relatively narrow 200 point range over the past month as the risks associated with the euro zone, economic growth and earnings make investors reluctant to push it higher.
On individual stocks, analysts are starting to reconsider whether companies still look attractive after the summer rally, prompting a downgrade on Aggreko by HSBC and on Sage
by Bank of America Merrill Lynch.
"At current levels, the risk reward (on Sage) is even, in our view, with this potential upside balanced by risks from a weaker macro in Europe, particularly in Spain and long-term threats from on-demand solution vendors," Merrill analysts wrote, downgrading the software firm to 'neutral' from 'buy'.
Investors wishing to more broadly protect their profits could do so via options, taking advantage of relatively cheap pricing, with UBS recommending a put-spread structure.
From a technical point of view, the market is not yet looking negative, with the 50-day moving average serving as a floor on Tuesday.
"Given we came off the trend line off the highs in September, the price action so far is a little bit disappointing. That said ... above 5,800, I'd be tempted to give it the benefit of the doubt," said Phil Roberts, technical strategist at Barclays.
(Additional reporting by Alistair Smout; Editing by John Stonestreet)
Keywords: MARKETS BRITAIN STOCKS/MIDDAY