* SNB keeps cap, target rate for Libor on hold
* Tone of statement more optimistic -economist
* SNB trims inflation outlook for 2014, 2015 as franc high
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By Alice Baghdjian
ZURICH, March 20 (Reuters) - The Swiss National Bank kept its lid on the Swiss franc at 1.20 per euro and its target rate close to zero on Thursday, but struck a slightly more optimistic note for the economy's prospects in coming quarters.
The central bank reiterated its standard line that it would defend the 1.20 per euro limit with unlimited interventions and stood ready to take further measures if necessary.
The SNB put a cap on the soaring franc in September 2011 to help stave off recession and the threat of deflation and had to intervene heavily in 2012 as the euro zone crisis flared.
Though the bank cautioned there were still substantial risks attached to the global economic recovery, some economists noted a positive shift in tone.
"The SNB is a bit more optimistic about Switzerland's prospects," said Alessandro Bee, an economist at J. Safra Sarasin.
"In December, they cited downside risks for Switzerland given the vulnerable economic situation abroad, but that has been dropped from this statement."
The SNB said economic activity in Switzerland should pick up again from the first quarter and confirmed its forecast that the Swiss economy would grow by around 2.0 percent this year.
Switzerland's economy stumbled in the fourth quarter of last year as exports fell, but other indicators, such as the forward-looking KOF, have pointed to an upturn going into 2014.
Swiss exports jumped 8 percent in real terms in February, separate data released on Thursday showed, lifted by robust sales of chemicals and pharmaceuticals, the country's largest export category.
The SNB kept its target range for the three-month Libor at 0.00-0.25 percent, as analysts polled by Reuters all expected.
On Wednesday, U.S. Federal Reserve Chair Janet Yellen pointed to a more aggressive path toward higher interest rates than markets had anticipated, sending stocks and bonds tumbling.
The SNB trimmed its inflation forecasts for this year and next by 0.2 percentage points each, predicting stable prices of 0.0 percent in 2014 and a rise of 0.4 percent in 2015. It expects prices to rise 1.0 percent in 2016.
The forecast is based on the assumption that the three-month Libor rate will remain at zero and the franc will weaken over the next three years, the SNB said.
"They are explicitly building a weaker Swiss franc into their forecasts, otherwise the monetary policy statement is more or less unchanged, as expected," said economist Reto Huenerwadel at UBS.
The SNB repeated that the franc was still high, which, along with internationally declining inflation rates, was keeping prices from climbing for now.
A crisis in Ukraine has pushed the currency closer to its 1.20 per euro limit in recent days, underscoring the safe-haven franc's exposure to turmoil overseas. It was trading at 1.2194 against the euro by 1030 GMT on Thursday.
"With the three-month Libor close to zero, the minimum exchange rate continues to be the right tool to avoid an undesirable tightening of monetary conditions in the event of renewed upward pressure on the Swiss franc," the SNB said in its statement.
(Additional reporting by Caroline Copley and Katharina Bart; Editing by Catherine Evans)
((alice.baghdjian@thomsonreuters.com)(+41 58 306 7461)(Reuters Messaging: alice.baghdjian.thomsonreuters.com@reuters.net))
Keywords: SWISS RATES/
