* FTSEurofirst 300 flat after setting 6-year highs
* Dax hits all-time high
* Strong results from Richemont, Aegon, H&M help support sentiment
LONDON, May 15 (Reuters) - European stocks turned flat as upbeat corporate earnings from blue chips such as jeweller Richemont contrasted with mixed GDP figures.
Traders were looking to euro zone GDP and inflation figures, both due at 0900 GMT, to gauge the odds of more monetary stimulus from the European Central Bank. The prospect of ECB action has lifted stocks in the past week.
Insurers Aegon, clothing retailer H&M and jeweller Richemont traded from 2.4 percent to 4.7 percent higher after releasing their results.
"Results will provide support, but the focus today is on the economic data," Mike Reuter, a broker at Tradition said. A weaker euro zone GDP reading could be seen as creating room for fresh stimulus in June, supporting stocks, he said.
The pan-European FTSEurofirst 300 index was flat at 1,368.06 points at 0820 GMT after reaching a fresh six-year high at 1,372.81 points earlier in the session. Germany's Dax was also flat after hitting an all-time high at 9,810.29 points.
Over the past week, European indexes have been boosted by speculation the ECB may cut rates and announce other measures at its June meeting. The central bank has said any move would depend on economic data, putting the euro zone GDP figures and inflation figures under scrutiny.
France's and Italy's GDP readings came in under forecasts. But German economic growth doubled to 0.8 percent quarter on quarter, beating consensus estimates.
Europe bourses in 2014: http://link.reuters.com/pap87v
Asset performance in 2014: http://link.reuters.com/gap87v
Today's European research round-up
(Additional reporting by Blaise Robinson in Paris; Editing by Larry King)