Ukraine and its biggest lenders appeared to be making cautious but steady progress Tuesday toward a debt restructuring deal that would save the war-torn country from hurtling into default.

The Wall Street Journal reported Monday that a group of commercial creditors holding nearly half of the $19 billion (16.5 billion euros) in debt under negotiation have offered to take a 20 percent write-down on the face value of their bonds.

German economic growth picked up in the second quarter of 2015, and the public finances of Europe's economic powerhouse were firmly in the black in the first half, data showed on Tuesday.

German gross domestic product (GDP) expanded by 0.4 percent in the period from April to June, up from 0.3 percent in the first quarter, the federal statistics office Destatis said, confirming a flash estimate released earlier this month.

A roller-coaster ride on global markets, which saw some bourses record their largest one-week losses since 2008 as they took fright at a Chinese sell-off, have raised fresh worries over the strength of the global economy.

And while analysts said fears of a repeat of the financial crises of 1997 or 2008 were largely unfounded -- mainly because of reforms undertaken since -- they warned that continued turbulence emerging from China would take a toll on global economic growth, especially in emerging economies.

Former Chinese vice finance minister Jin Liqun has been elected to head the new Asian Infrastructure Investment Bank (AIIB), the Chinese government said Tuesday. 

Jin was elected as the bank's "incoming president" at a two-day meeting of chief negotiators in the Georgian capital of Tbilisi, according to a statement by China's finance ministry. 

The vast majority of business economists expect the Federal Reserve will raise interest rates before the end of the year, according to a survey released Monday.

Minutes from the Fed's meeting in late July showed that officials could raise rates as early as September. Seventy-seven percent of survey respondents believe the Fed will raise rates from their current near-zero levels, but only 37 percent of respondents believe it will happen as soon as next month.

Asian stocks nosedived on Monday, led by sharp falls in Shanghai as concerns mount over the health of China's economy -- the world's second largest.

Russia's battered ruble dropped Monday to its lowest point this year as Asian and European stock markets nose-dived over concerns about the Chinese economy.  

Russia's dollar-denominated RTS index fell 4.21 percent at opening as the ruble tumbled to 70.92 against the dollar, its weakest against the greenback since December 2014. 

Chinese authorities are pursuing separate corruption cases against two top officials including the brother of a former top aide to ex-president Hu Jintao, state media reported Friday, as a crackdown on graft continues.

The Communist Party's corruption watchdog said that Ling Zhengce, former vice chairman of an advisory body to the local legislature in the northern province of Shanxi, had been expelled from the party for abusing his position and taking bribes, the official Xinhua news agency reported, a move which signals future criminal prosecution.

Rebels from Greece's Syriza party on Friday formed a breakaway parliamentary group after Prime Minister Alexis Tsipras resigned, paving the way for the crisis-hit country's fourth election in three years.

The fresh political uncertainty shook the markets, with stocks in Athens shedding 2.5 percent, while Greece's European creditors urged it to implement the terms of the massive new bailout whoever wins the poll likely to be held on September 20.

The former head of MtGox reportedly faced fresh criminal charges Friday over allegations he stole $2.6 million from clients, as police questioned him about hundreds of millions of dollars worth of missing Bitcoins.

Japanese authorities issued a fresh arrest warrant for France-born Mark Karpeles, over claims he stole millions from clients before the Bitcoin exchange collapsed, local media reported, including about $48,000 he allegedly spent on a luxury canopy bed.