Frankfurt  - The European Central Bank said Wednesday it sold 33.5 tons of gold up to end of March.

At a price of around 28,600 dollars per kilo, the sale fetched an estimated 1 billion dollars.

The ECB said the sale was in full conformity with a 2004 agreement among central banks restricting their annual sales of gold.

Central bank gold stocks are part of their currency reserves.

In the 2004 agreement, the ECB, eurozone central banks and those of Switzerland and Sweden agreed to limit their combined annual gold sales to 500 tons for a period of five years. (dpa)