* FTSEurofirst down 0.4 pct, reversing Tuesday's gains * German bond auction highlights investor caution * Natixis says 2013 EPS consensus too optimistic By Toni Vorobyova LONDON, Nov 14 (Reuters) - European shares slipped back from the previous session's gains on Wednesday, as anti-austerity strikes across southern Europe and Greece's unresolved debt crisis eclipsed some reassuring corporate results. Strikes in Spain and Portugal shut schools and grounded flights across the Iberian peninsula, while international lenders continued to disagree over how long to give Greece to get its debts down to a sustainable level. Investors also remain concerned about whether the U.S. government can avoid falling off the "fiscal cliff" of some $600 billion in automatic tax hikes and spending cuts which threaten to plunge the world's biggest economy back into recession next year. Cyclical sectors, demand for whose products and services depends on global economic strength, were amongh the worst performers, with basic resources down 1 percent and personal and household goods down 0.8 percent. The FTSEurofirst 300 was down 0.4 percent at 1,094.32 points by 1101 GMT, eroding Tuesday's rise which was its first daily gain in a week. The ex-dividend factor added to the market's fall, with trading in shares in Shell and Irish budget airline Ryanair going ex-dividend on Wednesday, meaning new investors do not get the latest payout. "A quick solution for the U.S. fiscal cliff doesn't seem to be on the cards and (there are) ongoing worries about Greece and renewed concern about Spain," said Zeg Choudry, head of equites trading at Northland Capital. "Yesterday afternoon the market looked ready to bounce but it needs a bit of relief from the poor sentiment that the bad news is causing." The cautious sentiment was highlighted by a German bond auction, where investors accepted negative yields on two-year debt, choosing the relatively safehaven over higher return but higher risk assets. The euro zone crisis has taken its toll on third-quarter company profits in the region, with German utility E.ON extending losses a day after a warning of weaker power demand in the region unleashed a string of ratings and target price cuts. But investors found some reassurance from German chipmaker Infineon, which announced results in line with forecasts and cost cutting plans. They also welcomed forecast-beating results at Vivendi and Telekom Austria, boosting their share prices. So far in the quarterly reporting season European companies have beaten earnings forecasts by an average of 2.1 percent, according to Thomson Reuters Starmine data, although that masks disappointments in the energy, materials and consumer-discretionary sectors. "Concerning earnings season, yes, it is not so bad. But outlooks are gloomy, and ... consensus is clearly over optimistic for 2013 with 11 percent earnings per share growth expected," said Benoit Peloille, investment strategist at Natixis. "So, optimism for equities as an asset class is justified ... but upside is limited by still very poor growth prospects."