* FTSEurofirst 300 down 0.8 pct, Euro STOXX 50 down 1.1 pct
* Saint-Gobain falls 3.5 percent after Groupama placing
* Carrefour hit by profit takers ahead of results
By Francesco Canepa
LONDON, April 8 (Reuters) - European shares fell for a second day on Tuesday, with building materials group Saint-Gobain among the worst hit, as investors sold out of some this year's best performers for fear the upcoming earnings season would deliver sobering news.
Saint-Gobain declined 3.5 percent as French insurer Groupama sold its 1.8 percent stake in Europe's biggest supplier of building materials. The shares went for around 44.50 euros, a 3.2 percent discount to their closing price on Friday.
The stock had risen 28 percent between early December and last Friday. "We thought the price was quite low, and we had a few clients getting out of their positions (in Saint Gobain)," said Ishaq Siddiqi, market strategist at ETX Capital.
The stock's retreat was among the biggest on the pan-European FTSEurofirst 300, which was down 0.8 percent at 1,325.72 points at 1100 GMT. The euro zone Euro STOXX 50 index was down 1.1 percent at 3,150.10 points.
Both indexes reported their worst daily drop in a month on Monday as investors took profit on a nine-day rally, fearing the market had got ahead of itself and the upcoming first-quarter results would expose fundamental weaknesses.
A stock market surge in 2013 and in part of this year has left the MSCI Europe dollar-denominated index trading at 13.9 times its expected earnings for the next 12 months, the highest valuation multiple since 2005, Datastream data showed.
Earnings momentum for European shares has remained negative throughout the period, with analysts cutting their 12-month forward estimate for European stocks by 2.5 percent over the past three months, the data showed.
Selling pressure was highest on some of this year's best performers, such as French retailer Carrefour, which fell 3.6 percent before the company's results on April 10. The stock had risen nearly 20 percent between late January and last week.
The Moulin family, which controls French department store Galeries Lafayette, said late on Monday it had bought a 6.1 pct stake in Carrefour. The purchase was seen as a vote of confidence in Carrefour's strategy, but also triggered some profit-taking after the recent rise.
"The share rise ... was perhaps helped by the purchase in the market by the Moulin family, so the shares decline a little today," said Christian Devismes, an analyst at CM-CIC Securities. The family would not be able to increase its stake in Carrefour significantly, he said.
"Carrefour is going to report its quarterly figure the day after tomorrow and nobody expects good figures."
Euro zone banks, which have risen 20 percent since early December on growing bets on a recovery in the euro zone, were also under pressure.
Among sellers was Markus Huber, senior trader at Peregrine & Black, who expected negative surprises from the sector during the earnings season as a result of several investigations into market rigging and mounting regulatory pressure to increase transparency.
"We have yet to figure out whether this is just a normal correction ahead of the earnings season or it's something more serious," Huber said.
Simmering tensions in Ukraine also weighed on market sentiment after pro-Russian protesters in eastern Ukraine seized arms in one city and declared a separatist republic in another, moves the Ukrainian government described as part of a Russian-orchestrated plan to justify an invasion.
Austria's Raiffeisen Bank International, which features among the European blue-chips with the biggest exposure to Ukraine, fell 2.8 percent.
Europe bourses in 2014: link.reuters.com/pap87v
Asset performance in 2014: link.reuters.com/gap87v
Today's European research round-up (Editing by Mark Heinrich)