* FTSEurofirst 300 down 0.1 pct
* Investors bet that FTSE 100, DAX, CAC will fall - IG data
* French telecoms fall as price war looms
* SABMiller outperforms on strong sales update
By Francesco Canepa
LONDON, Jan 22 (Reuters) - European shares were slightly lower on Tuesday, weighed down by French telecoms stocks as the prospect of a price war in the sector loomed.
An unexpectedly strong survey of German sentiment, showing analyst and investor morale at its highest since May 2010, helped shares pare early losses by mid-morning trade, partly reversing a technical selloff that had started on Germany's Dax index.
Shares in France Telecom, Vivendi and Bouygues shed between 2.5 percent and 3.7 percent in brisk volume after the head of Vivendi's SFR mobile operator said it was slashing prices by as much as 25 percent.
They weighed on the pan-European FTSEurofirst 300 index of top European shares, which was 0.1 percent lower at 1,165.56 points at 1223 GMT. It has slipped from a near two-year high of 1,170.29 hit on Jan. 10.
Around Europe, Britain's FTSE 100 was flat, Germany's Dax shed 0.3 percent and France's CAC was 0.1 percent lower.
Investors were bracing for further losses on national indexes, data from spreadbetter IG showed.
Around 87 percent of investors on IG's trading platform were "short", or betting on a fall in the FTSE, which has outperformed its continental peers so far this year and was flirting with four-and-a-half years highs.
"People are sticking to their shorts because of how far we've come," Will Hedden, a sales trader at IG, said.
Shorts accounted for 66 percent and 71 percent of all DAX and CAC positions on IG's platform, respectively.
Charts also showed the FTSE was "overbought" based on its 14-day relative strength index, a momentum indicator.
Helping curb losses on the FTSE on Tuesday was global brewer SABMiller. It rose 1 percent after saying its overall revenues jumped 17 percent in the third quarter compared to last year, sustained by improving growth in its key Latin American markets.
European indexes had cut losses in mid-morning trade on the release of the closely watched German ZEW survey of analyst and investor sentiment, which rose sharply for a second consecutive month in January.
That suggested the euro zone crisis is no longer hitting Europe's largest economy as hard as in late 2012.
"The ZEW was very good and investors are hanging on every good news," Manoj Ladwa, head of trading at TJ Markets, said.
Investors may have turned overly bearish on the indexes and could be forced to close their short positions if good earnings news helps revives a rally in shares, Ladwa said.
With the European earnings season yet to start in earnest, traders said investors were focusing on results from the United States, where bellwethers such as Google, IBM and J&J were due to report.
"Everybody is looking at these numbers," Mark Priest, senior trader at ETX Capital, said.
"The reporting season has been pretty successful in America and I think that's what's helping to keep the market up."
Around 75 percent of the U.S. companies that have reported quarterly results so far have met or beaten analyst expectations, Starmine data showed.