U.S. authorities charged a former Chinese employee of tech giant IBM with economic espionage Tuesday for allegedly stealing proprietary source code to hand over to a Chinese government agency.

The Department of Justice said Xu Jiaqiang had been a developer for an unnamed U.S. company when he took the source code, intending to provide it to the Chinese National Health and Planning Commission, where he previously worked.

Wall Street tumbled a fourth straight day Tuesday as mounting worries over Britain's coming Brexit vote hit especially shares of big banks.

American Express lost 4.1 percent and Citigroup 2.8 percent, with the sector under pressure from low interest rates.

A third of Latin Americans who have risen out of poverty over the past 15 years could fall back into it due to the region's recession, a U.N. report showed Tuesday.

"We estimate there is a population of between 25 and 30 million citizens that today find themselves vulnerable to falling into poverty," said George Gray, the main author of the report and the chief economist for the UN Development Programme (UNDP) in Latin America.

Oil prices tumbled again Wednesday as traders grow concerned about the chances of Britain leaving the European Union while news of a surprise jump in U.S. stockpiles followed a warning of an extended period of global oversupply.

Saudi Arabia has approved rules opening its retail sector to greater foreign investment, official media said on Tuesday, as part of wide-ranging economic reforms.

Investors on Tuesday started paying for the privilege of owning rock-solid German government bonds as fears of a possible Brexit and economic worries caused a rush to the safety of German debt.

Tensions over trade and Chinese investment in a German robotics firm dominated Chancellor Angela Merkel's visit to Beijing Monday, with differences about steel and China's future market status on display.

The pound dropped to a two-month low and the yen rallied Monday as jittery investors shifted into safer assets on worries about Britain's possible exit from the European Union.

Oil prices slipped again Monday, extending last week's losses and mirroring a sell-off across Asian markets fueled by worries about the global economy, Britain's future in the EU and producers bringing more rigs back online.

Kuwait has asked the public prosecutor to open an investigation into a scrapped deal with U.S. firm Dow Chemical that resulted in a $2.2 billion fine, a newspaper reported Sunday.