Fears that Greece will not be able to meet the terms of bailout loans agreed to last year have sent world stocks tumbling and sharply lowered the value of the euro.

Markets in Asia were down sharply, with the key Hong Kong index off more than four percent. European indices opened lower and kept on falling, with most showing losses around four percent.

Bank stocks have been particularly hard hit by the looming possibility of a Greek default, as investors fear rating agencies could downgrade bank credit ratings because of loans to Greece. German government officials in particular have been meeting to draft plans to shore up that countries banking sector in the event of a Greek collapse.

Signs that European policymakers are divided on how to deal with Greece’s financial woes sent the euro to seven-month lows against the dollar Monday.

Oil prices fell by more than $2 a barrel because of concerns about Europe’s debt crisis and slowing global economic growth.

U.S. stock futures also fell, indicating that U.S. markets will open lower Monday, continuing last week’s losses.