* FTSEurofirst 300 flat
* Erases early losses after strong PMIs from Germany, euro zone
* Michelin, Unilever fall, flag weak EM demand
By Francesco Canepa
LONDON, Oct 23 (Reuters) - European stocks were flat in choppy trade on Thursday as better-than-expected euro zone business activity data helped offset some weak corporate results from companies such as French tyre-maker Michelin.
Euro zone businesses performed much better than expected this month but did so by slashing prices again, and optimism about the future fell to its lowest level in over a year, surveys showed on Thursday.
Earlier data showed Germany's activity increased in both the manufacturing and services industries, but France's business downturn deteriorated.
"Germany saved the day but people are still bearish and I think we are going to see some more weakness," Mike Reuter, a broker at Tradition, said.
The pan-European FTSEurofirst 300 index was flat at 1,308.28 points at 0832 GMT, hovering some 7 percent above a 13-month low hit last week.
Weakness in emerging markets remained a drag on European companies, however.
Michelin and Unilever cited poor demand from emerging markets as the former cut its full-year revenue goal and the latter reported weaker-than-expected quarterly sales. Unilever's London-listed shares were down 2.4 percent, while Michelin shed 3.6 percent.
Britain's biggest grocer Tesco and French advertising group Publicis also fell sharply after reporting disappointing numbers.
Among a handful of outperformers, Finland's Nokia beat market expectations as it reported strong third-quarter profit growth and lifted the profitability outlook for its core network unit on the back of network roll-outs in North America and China, sending its shares up 5.3 percent.
Danish industrial enzymes maker Novozymes also reported third quarter earnings above expectations and raised its full-year outlook for operating profit growth. Its shares rose 6.6 percent.
Europe bourses in 2014: link.reuters.com/pap87v
Asset performance in 2014: link.reuters.com/gap87v
Today's European research round-up (Reporting By Francesco Canepa; Editing by Janet Lawrence)