ATHENS, July 29, 2008 (AFP) - Greeks are still clinging onto nearly 250 million euros (393 million dollars) in old drachmas six years after the currency was phased out to be replaced by the euro, the Bank of Greece said on Tuesday.

'People should start checking their mattresses,' the Bank's head cashier

Apostolis Kakavoutis told state television NET, noting that 85 billion drachmas, or 249.5 million euros, remain to be exchanged.

Around 680 million drachmas have been redeemed since January and the option remains open until March 1, 2012, he added.

First appearing in Asia Minor in the seventh century B.C. and said to be the world's oldest currency, the drachma was removed from use in February 2002 when Greece completed a transition to the euro.