National Bank of Greece 27.33% ( NYSE: NBG)
Coca-Cola Hellenic Bottling 19.97% (NYSE: CCH)
OPAP 15.59%
Alpha Bank 9.39%
Hellenic Telecom 8.62%
Bank of Cyprus 7.81%
Public Power Corp. 6.01%
EFG Eurobank Ergasias SA 5.29%
So you can get a pretty good exposure (about 47.3 %) with top two companies on NYSE.