In a previous discussion on National Bank of Greece's (NYSE: NBG) fourth quarter, I compared it with a flickering flame struggling to keep itself from getting smothered. But I was reluctant to be too optimistic since a flame usually gives a final flutter before getting snuffed out.

Surprisingly, the Greek bank has showed resilience by posting yet another profitable quarter. This is in spite of the hellish environment that the larger nation is facing with an ever-problematic sovereign debt crisis.

Overall performance
The bank's net income rose to $222 million -- a whopping 39% increase on a year-on-year basis. At a time when the eurozone's banking system is still singing the blues, NBG has managed to post its fifth consecutive quarterly profit. Although the group's tier 1 capital ratio slid, as compared to the last quarter, it still remains at a comfortable 12.9%, reflecting a relatively strong capital base.

Digging deeper
NBG's Turkish subsidiary Finansbank once again balanced out the group's weak home-court performance. Within the segment, Finansbank's reduced provisions and robust credit expansion helped net profit increase by 28% to $216 million. Retail lending increased significantly by 37%, with mortgage lending up by 29%. Finansbank's business lending also grew by 16% during the quarter. This was a strong overall performance for the segment.

The bank's Southeast European subsidiary also managed to pull off a profit of $8.6 million in the quarter. This was a decline of 81% from the corresponding quarter of 2010 that was due to a fall in interest income and contraction of the loan book by 4%. The decline in net interest income was primarily due to sluggish credit expansion and amplified costs of deposits. However, the parent company was able to decrease funding to the subsidiary by $980 million as compared to the first quarter of 2010, which should be considered a moral victory of sorts.

Performance at home, however, still remains dreary as NBG reported a profit of just $2.8 million -- the least among the three reporting segments. However, looking at the brighter side of things, this is a considerable improvement from a net loss of $57 million in the corresponding quarter last year. Operating expenses declined by 8% year on year but provisions zoomed 41%.

The Foolish bottom line
At the moment, Greece seems to be the epicenter of the economic furor in the eurozone. Mounting Greek debts have now become insurmountable, and European officials are warning against a restructuring since it may prove undesirable for the whole eurozone.

It is the exposure of the Greek banks to their own sovereign debt and their larger consumer environment that makes me very reluctant to even back this relatively strong performance. In fact, banks of the other PIIGS nations such as Bank of Ireland (NYSE: IRE) and Allied Irish Bank (NYSE: AIB) are the last bets I would put my money on. So, in spite of yet another impressive show by NBG, I remain on the sidelines.

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Fool contributor Zeeshan Siddique does not own any of the stocks mentioned in the article. The Motley Fool owns shares of National Bank of Greece SA. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.