The International Monetary Fund and conflict-torn Ukraine have reached a preliminary deal on a new financial rescue plan worth $17.5 billion that could be a "turning point" for Kiev, IMF chief Christine Lagarde said Thursday.

In total, Ukraine will receive $40 billion (35 billion euros) in assistance over four years coupled with bilateral loans from other sources, Lagarde said, helping to stabilize Kiev's finances after 10 months of conflict in the east.

A former HSBC employee who leaked documents alleging the bank helped wealthy customers dodge tax said Wednesday he had tried to alert British authorities about evasion in 2008.

The leaks about the Swiss arm of Britain's largest bank have caused shockwaves across the world and sparked a political furore in London.

Inflation in Germany, Europe's biggest economy, dipped into negative territory in January for the first time in five years, largely due to lower energy prices, data showed on Thursday.

The annual rate of inflation in Germany stood at -0.4 percent last month, the federal statistics office, Destatis, calculated in final data.

Greece plans joint military exercises with Israel, Cyprus and Egypt, Greek Defense Minister Panos Kammenos said Wednesday, amid continuing tensions between Cyprus and Turkey over oil exploration in the eastern Mediterranean.

Kammenos, visiting close ally Cyprus, said the two countries, along with Israel and "possibly" Egypt would begin joint exercises within the coming months aimed at improving regional security.

A power blackout hit most of the energy-rich Gulf state of Kuwait Wednesday, disrupting traffic and a number of vital facilities but without affecting oil installations.

The electricity and water ministry said a technical problem at one of the country's five power plants forced it to cut power as a precautionary measure to protect the network, according the KUNA news agency.

Low oil prices normally help grease the wheels of business and spur global economic growth, but Moody's said Wednesday it would not revise its forecasts for the G20, citing a variety of offsets to the expected windfalls.

"For the G20 economies, we expect GDP growth of just under 3.0 percent each year in 2015 and 2016, unchanged from 2014 and from our November 2014 Global Macro Outlook," the credit ratings agency said in its latest outlook report.

Oil prices rebounded in Asia on Wednesday following a sharp decline in the previous session, analysts said, as investors await a weekly U.S. stockpiles report later in the day.

U.S. benchmark West Texas Intermediate (WTI) for March delivery rose 44 cents to $50.46 a barrel while Brent crude for March rose 16 cents to $56.59 in afternoon trade.

The euro rose in Asia Wednesday, with investors awaiting talks between Greece and its creditors over renegotiating a bailout deal, while the dollar firmed against the yen on expectations the Federal Reserve will hike interest rates.

The euro bought $1.1318 and 135.31 yen in afternoon Singapore trade, against $1.1315 and 135.15 yen in New York late Tuesday, while the greenback rose to 119.55 yen from 119.44 yen.

Kiev has requested a restructuring of its debt to Russia but Moscow is expecting its $3 billion loan to be repaid in full this year, Russia's finance minister said Tuesday.

"Ukraine asked us to review the issue of restructuring its debt," Finance Minister Anton Siluanov told Russian media on the sidelines of the G20 summit of finance ministers and central bank chiefs in Istanbul.

Standard and Poor's has lowered the outlook for the world's top oil exporter Saudi Arabia to negative and downgraded its Gulf partners Oman and Bahrain on sliding oil prices. 

But despite the large budget deficit planned by Riyadh for this year, the agency maintained its sovereign credit ratings for the kingdom, as well as neighboring Abu Dhabi and Qatar, citing their "very strong fiscal positions."