The European Central Bank has restored a key waiver that will let Greek banks tap emergency central bank credit, one step toward putting the country's financial institutions back on their feet.

The decision announced Wednesday permits Greek government bonds to be used by banks as collateral to get cheap money from the ECB — even though those bonds are rated too low under the usual rules.

Greek banks were shattered by the country's financial and debt crisis which has led to three bailouts since 2010. They have been relying on more expensive financing from the Greek national central bank to do business. The ECB restored the waiver after the Greek government got a 7.5 billion euro installment on its latest bailout, ensuring the government can pay its bills for now.