Twitter on Thursday reported its revenue nearly doubled in the final three months of last year, but user growth fell short of analyst expectations.

Twitter shares rallied more than 10 percent in after-market trades, evidently powered by an optimistic outlook painted by executives who expected user growth to ramp and who confirmed an alliance with Internet search titan Google.

Oil prices extended their gains on Friday at the end of a volatile week for the commodity, while the euro held its own after the European Central Bank made assurances that Greek banks would have access to much-needed funds.

Investors seemed to shrug off a clash between Greece's new finance minister and his German counterpart over renegotiating Athens' debt, while a strong rally on Wall Street provided some support to regional markets.

South Africa's national news agency SAPA Thursday announced it will shut down at the end of next month because of financial problems.

"The company will be liquidated and its operations will cease on March 31, 2015," South African Press Association (SAPA) board chairwoman Minette Ferreira said in a statement.

The EU raised its growth forecast for the eurozone on the back of cheap oil and a weak euro, but warned that with deflation taking hold the bloc's struggling economies must keep up their reforms.

Economic Affairs Commissioner Pierre Moscovici said France must take further steps to reduce its budget deficit and that Greece's new government must respect its commitments to its creditors as global alarm over the debt crisis mounts.

The Greek stock market plunged more than nine percent in early trading on Thursday after the European Central Bank moved to restrict Greek banks' access to a key source of cash.

After opening slightly down, the Athex general index slid by 9.43 percent to 768 points, before recovering some of its losses.

Athletic clothing maker Under Armour on Wednesday announced it is building its digital muscle with a pair of fitness application makers.

Under Armour said that it is paying $475 million for San Francisco-based MyFitnessPal and that it paid $85 million for Endomondo in Copenhagen.

Oil turned lower in Asia Thursday as an early rally fizzled out after the euro was hit by fresh concerns over Greece, further hurting demand in the face of an oversupply, analysts said.

U.S. benchmark West Texas Intermediate (WTI) for March delivery was down 32 cents to $48.14 in afternoon trade and Brent crude for March tumbled 16 cents to 54.03. Both contracts started higher in early Asian trade.

Middle Eastern and North African states are expected to invest $755 billion in energy projects over the next five years despite the plunge in world oil prices, a key lender says.

The Arab Petroleum Investments Corporation (APICORP) said its projection for the 2015-19 period was only slightly down on the $760 billion that it forecast for 2014-18, although estimates for the coming period have been slightly inflated by an increase in project costs.

Kingdom Holding Co, chaired by billionaire Saudi Prince Alwaleed bin Talal, has reduced its stake in Rupert Murdoch's media giant News Corp over the past year, the Riyadh-based firm said Wednesday.

Kingdom's stake has fallen from more than 13 million Class B shares, or about 6.6 percent, to two million shares, which represent about one percent ownership, a statement said.

Asia extended a global stocks rally Wednesday while the euro held on to healthy gains as hopes grow that Greece will be able to hammer out a debt deal with its European partners.

Traders followed the lead from across Europe and the United States after Greece's new leadership impressed with their charm offensive aimed at getting backing for a renegotiation of its bailout.