European stocks opened slightly lower on Friday, with lingering worries about Greece securing its bailout from international creditors, and slumping prices for commodities weighing on investor sentiment.
In initial trades, London's benchmark FTSE 100 index inched 0.05 percent lower to 6,651.83 points compared to Thursday's close, while Frankfurt's DAX 30 dipped 0.38 percent to 11,467.83.
The CAC 40 in Paris slipped 0.23 percent to 5,075.25 points, though shares in electrical systems giant Thales surged seven percent after its first half results showed promising activity for the rest of the year.
In foreign exchange the euro was trading at $1.0976, slightly higher than its $1.0966 level in New York late Thursday.
Europe's main markets closed mixed Thursday in subdued trading over continuing concern about Athens finalising a bailout deal with creditors, despite Greece's Syriza-dominated parliament having voted through the second of two sets of tough reform packages earlier in the day.
On Friday, the so-called "troika" of Greek creditors -- the International Monetary Fund, European Union and European Central Bank -- arrived in Athens to begin negotiating the complex and contested details of a third bailout to Greece worth up to 86 billion euros ($93 billion).
"The dreaded troika... returned to Greece this morning to officially begin negotiations for a third bailout," said Spreadex analyst Connor Campbell.
"Just six months after Syriza’s election victory and... emphatic declaration that the country would no longer negotiate with the triumvirate comprised of the European Commission, ECB and IMF they are back once again, holding with them the keys to unlock the desperately needed fresh bailout package."
Traders were also mindful of volatile activity in commodity markets, where the stronger dollar pinched prices, even as oil recovered slightly.
"The issue of falling commodities has replaced Greece and Chinese equity volatility as the centrepiece of the capital markets. This seems to be premised on a toxic mix of increasing future surplus figures (in the forecasts), but Chinese growth and concern of a September move from the Federal Reserve are also in play," said Chris Weston, chief market strategist for IG.
"The talk among traders once again has been around moves in commodities and what that is saying about global growth."
Asian stocks mostly fell Friday after weak manufacturing data from China, adding to concerns about the mainland economy.
Tokyo shed 0.67 percent to end at 20,544.53, Sydney fell 0.43 percent to close at 5,566.1 and Seoul was 0.93 percent lower to 2,045.96.
Asian and European bourses were also responding to Wall Street's lower close Thursday, when US stocks fell for a third straight session on the back of disappointing earnings from Caterpillar, American Express and others.