(Adds details, updates prices)
* FTSEurofirst 300 and Euro STOXX fall
* China's weakness still affecting mining stocks
* Actelion up after raising earnings forecast
* Athens index outperforms on stronger banks
By Sudip Kar-Gupta and Danilo Masoni
LONDON/MILAN, Oct 20 (Reuters) - European shares fell on Tuesday after reaching five-week highs the day before, as both energy and mining stocks extended losses caused by weak economic date from China.
The pan-European FTSEurofirst 300 index opened flat, then lost ground to fall 0.48 percent. The euro zone's blue-chip Euro STOXX 50 index < .STOXX50E> fell 0.56 percent.
Traders said shares dropped as investors took profits in the absence of anything to justify extending the recent gains. The focus remains on U.S. earnings and the European Central Bank meeting this week.
Mining stocks fell for a second day after China reported on Monday third-quarter economic growth was the slowest since the global financial crisis. China is the world's leading consumer of metals.
"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.
Major energy stocks such as BP and Total fell as oil prices steadied after dropping for a week. The world's biggest independent oil trader said the market would struggle to recover ground over the next year.
Actelion rose 3.8 percent after Europe's biggest biotech firm raised its full-year earnings forecast as sales of a new lung and heart drug beat expectations.
SAP edged up 0.9 percent after Europe's biggest software group said it may surpass full-year financial targets in the fourth quarter.
UniCredit rose 2.7 percent after reports the Italian lender may sell some of its Austrian assets.
Satellite companies Eutelsat and SES fell 5.7 and 4.2 percent respectively after Goldman Sachs downgraded both to "sell" from "neutral".
The Athens blue-chip index rose 1.2 percent, outperforming the rest of Europe, as banking stocks gained after Reuters reported that re-capitalising the country's four main banks will cost less than 20 billion euros.
Both the FTSEurofirst and the Euro STOXX 50 remain up by around 5 percent since the start of 2015, helped by the European Central Bank's stimulus programme.
The ECB has pumped cash into the euro zone and kept interest rates at a record low to bolster the economy. Traders expected the ECB to pledge similar measures at its meeting on Thursday.
Credit Suisse's European economics team said in a note it expected ECB head Mario Draghi to "sound very dovish" at the meeting, preparing the ground to disclose further economic stimulus measures in December.
Today's European research round-up
Additional reporting by Maria Pia Quaglia in Milan, editing by Larry King