Thousands marched as a crippling general strike against pension reforms swept Greece on Thursday, with hooded youths lobbing firebombs at riot police in scattered skirmishes in the capital.

Some 40,000 people from all walks of life joined protests in Athens and another 14,000 demonstrated in Thessaloniki for the 24-hour industrial action, police said, as riot officers in the capital fired tear gas in response to the Molotov cocktails.

The International Monetary Fund (IMF) urged Portugal on Thursday to do more to spur economic recovery, voicing concern over a "loosening" of budget discipline by the new Socialist-led government.

"Portugal needs to build on the progress made in recent years in stabilizing the level of public debt through its successful fiscal adjustment," an IMF delegation said following a week-long mission to Lisbon. 

Swiss banking giant Credit Suisse on Thursday posted a net loss of nearly $3.0 billion for 2015, hit by hefty litigation provisions and restructuring charges, sending its share price down more than 12 percent.

Switzerland's second largest bank posted a net loss of 2.9 billion Swiss francs ($2.9 billion, 2.6 billion euros) for the year, compared to a net profit of 1.8 billion francs in 2014. 

The biggest trade deal in history was signed Thursday, yoking 12 Pacific rim countries in a U.S.-led initiative aimed at wresting influence from booming China.

The ambitious Trans Pacific Partnership (TPP) aims to slash tariffs and trade barriers for an enormous 40 percent of the global economy -- but pointedly does not include Beijing.

Oil prices extended their rebound in Asia Thursday, buoyed by a weaker dollar, bargain buying and fresh speculation of a possible output cut by the OPEC producers' group.

Traders brushed aside bearish data showing another increase in U.S. commercial crude inventories, but analysts said any rally in a market awash with barrels of oil is bound to be short-lived.

Re-establishing European borders as a result of the migration crisis could cost France more than 10 billion euros per year, according to a study published on Wednesday.

The vast influx of refugees and migrants has seen calls grow for Europe's borderless Schengen zone to be abandoned and tougher immigration controls imposed. 

Japan's central bank said Wednesday it was investigating a high-profile media report that revealed it was mulling a negative interest rate policy just before it made the formal announcement.

The country's leading Nikkei business daily published its story online Friday, several minutes before the central bank shocked markets with the surprise stimulus after a closed-door meeting. 

Ukraine's Lithuanian-born Economy Minister Aivaras Abromavicius abruptly submitted his resignation Wednesday citing his inability to push through vital restructuring measures essential to getting growth in the cash-strapped country on track.

The shock decision layed bare the sharp divisions with pro-Western President Petro Poroshenko's government and the difficulties the ex-Soviet nation faces in coming through with the changes needed to fulfil its ambition of joining the EU.

The oil price slump cast a cloud over Asian markets again Wednesday after falling back below $30 a barrel, hammering energy firms once again and sending stocks deeper into the red.

With the euphoria of Friday's Bank of Japan stimulus but a distant memory, Tokyo led the regional losses followed by Hong Kong, where insurance giant AIA lost almost a tenth of its value at one point on fears China would tighten insurance rules.

Alphabet, the parent firm for Google, became the world's most valuable company Tuesday as a jump in its share price helped it vault past tech rival Apple.

In opening trade following a robust earnings report, Alphabet shares rose 2.9 percent to lift its market capitalization to $543 billion while Apple's value declined to $530 billion with a modest dip in trading.