Prior to the late 1990's there were only 3 casinos in Greece and all used the "Greek Casinos" chips. After they authorized more casinos each casino used chips with their own name.

From ebay item.... http://www.ebay.com/itm/Obsolete-Greek-Casinos-E-O-T-/281046628526?pt=LH_DefaultDomain_0&hash=item416faf38ae