* FTSEurofirst 300 index falls 0.6 pct
* Tech sector is top decliner, tracks Nasdaq sell-off
LONDON, April 14 (Reuters) - European equities slipped to a three-week low on Monday, led lower by technology stocks following a sharp U.S. sell-off on the tech-heavy Nasdaq, with tensions in Ukraine prompting investors to shun riskier assets.
The STOXX Europe 600 technology index fell 1.6 percent, taking its losses since early April to more than 6 percent on concerns that valuations have become stretched.
Ericsson fell 4.3 percent, while ARM Holdings was down 1.7 percent, mirroring losses on the Nasdaq, which closed below 4,000 for the first time since early February on Friday.
The pan-European FTSEurofirst 300 index was down 0.6 percent at 1,305.24 points by 0826 GMT after falling to a three-week low earlier in the session and slipping 3 percent last week, with analysts saying that fresh tensions in Ukraine could prevent it from bouncing back in the near term.
Germany's benchmark DAX share index, which includes several companies with significant exposure to Russia, lagged the wider market and was down 0.8 percent.
"Geopolitical concerns are putting pressure on equities. Markets fear an escalation in tension will result in more economic sanctions on Russia and that will have a negative repercussion on Europe," Christian Stocker, equity strategist at UniCredit in Munich, said.
Ukraine gave pro-Russian separatists a Monday morning deadline to disarm or face a "full-scale anti-terrorist operation", while the UN's Security Council sat in emergency session.
Two other blue-chips exposed to Russia and Ukraine, Finnish tyre maker Nokian Renkaat and Austrian lender Raiffeisen Bank International, fell 1.9 percent and 3 percent respectively on Monday.
Greece's largest lender National Bank fell 11.3 percent, the biggest decliner on the FTSEurofirst 300, after a banker told Reuters on Saturday it was considering tapping international markets with a share offering as part of plans to plug a capital shortfall.
Glencore Xstrata gained 1 percent after selling its interest in the Las Bambas copper mine in Peru to a Chinese consortium in a $6 billion cash deal, making it one of China's largest mining acquisitions for years.
Despite recent jitters on Wall Street and simmering tensions in Ukraine, investors have continued to pour money into European equities, which attracted more than $1 billion in the week ended April 9, according to EPFR Global data.
Spain and Italy equity funds saw over $150 million each in net inflows, while Germany and UK funds suffered $250 million in redemptions, EPFR data showed.
Europe bourses in 2014: http://link.reuters.com/pap87v
Asset performance in 2014: http://link.reuters.com/gap87v
Today's European research round-up
(Editing by John Stonestreet)