Greece raised 4.387 billion euros ($5.7 billion) at little-changed interest rates on Tuesday with a special bond issue to pay current bills as the country's debt agency tries to finalise a debt buy-back having extended the deadline.

The debt agency borrowed the money via a one-month issue at 3.99 percent, a slightly higher rate than during its last comparable issue, and via a six-month issue at a slightly lower rate of 4.38 percent.

Meanwhile, the agency is due to conclude the Greek debt buy-back later on Tuesday, to unlock the latest instalment of urgently needed bailout funding from international creditors.