* Euro rises after well covered Spanish auction
* Stop-losses triggered through $1.2355/60
* Swiss franc up; SNB steps back from interventionist stance
(Changes lead, adds quotes, updates throughout)
By Neal Armstrong
LONDON, June 17 (Reuters) - The euro hit a three-week high versus the dollar on Thursday as worries about Spain's public finances were eased by a well covered bond auction, triggering stop-losses on stale short positions in the single currency.
The Swiss franc rose as the Swiss National Bank relaxed its interventionist stance and said deflationary risks in the Swiss economy had all but disappeared.
The spread of Spanish government bond yields over benchmark Bunds had soared to a euro lifetime high on Wednesday, but a well covered auction, albeit at a high yield, caused spreads to tighten and the euro to rally to a session high. "The auction went reasonably well but with rising yields it's not that much of a surprise. There are still worrying signs for Spain, particularly stresses in the Spanish bank funding market," said Lee Hardman, currency strategist at BTM-UFJ.
At 0950GMT, the euro was trading up around 0.6 percent versus the dollar at $1.2390, just off session highs. It had fallen to a low of $1.2243 as worries over Spain's public finances and banking sector hit sentiment in early trade.
"We think the euro rally is being driven by position adjustment rather than fundamentals in particular," added Hardman.
Traders said stop-losses which had been placed above this week's highs in the $1.2355/60 area had been targeted and triggered in the wake of the Spanish auction results.
The euro has now regained over 500 points from a four-year low hit on June 7 at $1.1876, but still holds losses of over 13 percent year-to-date.
The European Union and International Monetary Fund denied on Wednesday a report they and the U.S. Treasury were drawing up a safety net for Spain. But worries about Spanish banks put pressure on yields and the market will be looking for the results of bank stress tests which the Spanish central bank said would be published soon.
The European Union holds a summit on Thursday to discuss ways to strengthen budget discipline and economic policy coordination.
SWISS FRANC RISES
The Swiss franc rose versus the euro and the dollar after the SNB omitted specific reference to the currency in the statement accompanying its decision to leave interest rates on hold.
The SNB said deflationary risks had all but disappeared, implying its strict policy of currency intervention to prevent excessive appreciation in the franc may no longer be required.
"The fact that the SNB have said deflationary risks have all but disappeared for now is very bullish for the franc as deflationary risks were associated with intervention risk," said Audrey Childe-Freeman, senior currency strategist at Brown Brothers Harriman.
The euro fell from around 1.3877 francs to a session low of 1.3759, bringing the recent all time low of 1.3731 into focus. The dollar fell from around 1.1315 francs to a one-month low of 1.1128.
The dollar traded with losses of around 0.5 percent versus a currency basket as European stocks and US equity futures traded in positive territory.