* FTSEurofirst 300 and Euro STOXX both steady
* Actelion up after raising earnings forecast
* Weak China continues to impact mining stocks
By Sudip Kar-Gupta
LONDON, Oct 20 (Reuters) - European shares were steady on Tuesday, with biotechnology group Actelion climbing after it raised its earnings forecast although mining stocks extended losses in the wake of weak China data.
The pan-European FTSEurofirst 300 index was flat while the euro zone's blue-chip Euro STOXX 50 index edged up by 0.1 percent.
Actelion rose 4 percent after it raised its full-year earnings forecast as sales of its new drug to treat pulmonary arterial hypertension beat analysts' expectations.
However, miners such as Glencore and BHP Billiton fell for the second session in a row in the aftermath of data from China on Monday, which showed that growth in the world's leading consumer of metals was at its slowest since the global financial crisis.
"There is still the legacy of the weak Chinese data that is hanging over parts of the market today," said Hantec Markets' analyst Richard Perry.
Satellite companies Eutelsat and SES also fell after Goldman Sachs downgraded both stocks to "sell" from "neutral".
Signs of a Chinese slowdown knocked back European shares in the third quarter, but both the FTSEurofirst and the Euro STOXX 50 remain up by around 5 percent since the start of 2015, helped by supportive measures from the European Central Bank (ECB).
The ECB has pumped cash into the region's markets and kept interest rates at a record low to bolster the overall economy. Traders expected the ECB to pledge similar measures in the future at its meeting on Thursday.
Credit Suisse's European economics team wrote in a note that they expected ECB head Mario Draghi to "sound very dovish" at the Thursday meeting, preparing the ground to unveil further economic stimulus measures in December.
Today's European research round-up
Editing by Tom Heneghan