Friday is what's known as a "triple witching day" according to analysts. This means that contracts for stock index futures, stock index options and stock options all expire on the same day and can lead to market volatility.
"The fact that it is a triple witching day and we have the expiry of options is causing some strange moves in the markets," Craig Erlam, senior market analyst at currency trading firm OANDA, told CNBC.
The majority of European indices closed slightly higher on Friday, with London's FTSE 100 index closing around the flat line and the French CAC at 0.25 percent higher. The German DAX however was down by around 0.5 percent at the close.
An emergency summit of euro zone leaders is to be held on Monday following the failure of euro zone finance ministers, who met in Luxembourg Thursday, to reach a deal with Greece on completing its reform program. The reforms would allow Greece to receive a last tranche of bailout aid worth 7.2 billion euros but sticking points remain over pension cuts.
Read MoreFollow our live blog for more on the Greek debt crisis
Without the money, Greece has said that it will not be able to make a 1.5 billion euro debt payment to one of its senior creditors, the International Monetary Fund (IMF) on June 30.
The European Central Bank (ECB) held a teleconference on Greece Friday to discuss extending emergency liquidity to Greece and after a leading member of the bank expressed doubt whether Greek banks, which have suffered large capital outflows, could open Monday. Greece's stock exchange closed around 0.6 percent higher.
At the European close, U.S. stocks were trading mildly loweron Friday, as investors watched developments in the Greece debt talks.
In other news, the St. Petersberg International Economic Forum (SPIEF) continues in Russia with global business leaders in attendance. Greek Prime Minister Alexis Tsipras sharing a stage with Russian President Vladimir Putin. On Thursday, Russia's finance minister said that Greece has not asked it for financial aid.
Read MoreGreece's Tsipras heads to Russia for some love
The forum comes at a difficult time for Russia as it is still under international sanctions due to its annexation of Crimea last year and subsequent role in the pro-Russian uprising in east Ukraine, although it denies involvement.