* FTSEurofirst 300, Euro STOXX 50 both down 0.1 pct
* Selloff in U.S. tech stocks unsettle investors
By Francesco Canepa
LONDON, May 7 (Reuters) - European stocks edged lower on Wednesday, as a selloff on Wall Street unsettled investors and results from brewer Carlsberg and bank Societe Generale showed the Ukraine crisis was starting to hurt large western companies.
Shares in France's No. 2 listed bank fell as much as 2.3 percent as it booked a 525 million euro ($731 million) writedown on the value of its Russian unit Rosbank (MCX: ROSB.ME - news) , blaming heightened uncertainty and a decline in the rouble.
Danish brewer Carlsberg, one of Europe's blue-chips with the highest exposure to Russia, was also in the red as it lowered its net profit outlook after reporting a weaker-than-expected first quarter, capped by a weak rouble and declining sales in Eastern Europe.
"Overall these warnings had to be expected and there will likely to be more of them," Markus Huber, a senior sales trader at Peregrine & Black, said.
"It will be important to see if other sectors will start warning too, especially car manufacturers for whom Russia is a very important market."
Shares in global carmaker Fiat (Berlin: FIAT.BE - news) -Chrysler (Xetra: 710000 - news) dived 7.6 percent after it unveiled an ambitious plan to boost sales by 60 percent by 2018 by betting on premium brands such as Jeep and Alfa Romeo.
The pan-European FTSEurofirst 300 index was down 0.1 percent at 1,341.72 points, with the euro zone blue-chip Euro STOXX 50 also down 0.1 percent, at 3,146.88 points.
They mirrored a selloff on Wall Street, where Twitter (Berlin: TWR.BE - news) led a rout in tech stocks with a 17.8 percent tumble after the expiration of a six-month lock-up period for early investors.
The plunge in tech stocks raised the spectre of a repeat of the near 10 percent fall in the tech-heavy Nasdaq index earlier this year, which dragged down global stocks.
Traders, however, noted Tuesday's fall was in thin volume.
About 5.9 billion shares changed hands on U.S. exchanges, below the 6.2 billion average over the past five days, according to data from BATS Global Markets.
"It was a bit of a risk off but I don't think it'll necessarily (translate into) a big selloff because volumes were still down 20 percent on a normal day," Mike Reuter, a global broker at Tradition, said.
Personal (Other OTC: PRBDF - news) and household goods stocks helped put a floor under the market, as German consumer goods group Henkel (Berlin: HEN.BE - news) beat market expectations with results and Imperial Tobacco Group rose after its update.
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)