NEW YORK, Nov 3 (Reuters) - Moody's Investors Service said
on Tuesday that it may downgrade three Greek banks, following
its announcement last week that it may cut Greece's foreign and
local currency debt ratings.

Moody's placed the Aa3 deposit and debt ratings for
National Bank of Greece (NBGr.AT: Quote, Profile, Research) on review for downgrade, as
well as the A1 ratings for EFG Eurobank Ergasias SA (EFGr.AT: Quote, Profile, Research)
and the government-backed debt of Alpha Bank AE (ACBr.AT: Quote, Profile, Research)
rated A1.

The agency said it may cut Greece's A1 debt rating last
week, citing a sharp deterioration in fiscal data in the highly
indebted country. The action came one week after Fitch
downgraded Greek government debt.

The ongoing global financial crisis has shifted Moody's
approach to assessing the credit quality of large banks,
aligning bank ratings more closely with that of the sovereign.

Greece's mounting debt levels may impair the government's
ability to support an unstable banking system, Moody's said in
a release.

"A government's local currency debt rating should have a
greater weight when considering its ability to provide systemic
support," Moody's said in a statement.

A downgrade of Greek government debt would likely lead to a
downgrade of National Bank of Greece, EFG Eurobank Ergasias and
Emporiki Bank (CBGr.AT: Quote, Profile, Research), Moody's said.

In turn, Alpha Bank's government-guaranteed bonds would
also be affected by the sovereign action.
(Reporting by Camille Drummond; Editing by Theodore
d'Afflisio)