The European Central Bank said on Tuesday foreign currency reserves of the euro zone central banks in the week ending April 22 fell by a net 0.1 billion euros while its gold holdings were also down. The net position of the ECB and euro zone central banks in foreign exchange reserves totalled 159.1 billion euros at the end of the reporting week, the ECB said in its regular weekly consolidated financial statement. Gold reserves were 31 million euros lower at 127.96 billion euros, the bank said citing a sale by one central bank.