FRANKFURT Tue Jan 6, 2015 6:57am EST

German banks have about 23.5 billion euros ($28 billion) in credit exposure to Greece, but the systemic risk is limited because the biggest commercial banks, Deutsche Bank (DBKGn.DE) and Commerzbank (CBKG.DE), hold only a tiny fraction of that, according to figures gathered by Reuters.

The lion's share of German exposure is held by the state-owned development bank KfW, with lending to the Greek state totaling 15 billion euros, banking industry group BdB said.

Commerzbank said it held about 400 million euros in exposure to Greece at the end of September, while Deutsche Bank said it held around 298 million euros in corporate, bank and public debt.

Greek politics has weighed on markets including the euro as speculation intensified that Greece could leave the euro zone after a snap election on Jan. 25. [ID:nL6N0UK0YX]

A study by JP Morgan (JPM.N) found that French bank Credit Agricole (CAGR.PA) was the most exposed of Europe's commercial banks. Credit Agricole said it had 3.5 billion euros in exposure to Greece at the end of 2013, of which 2.8 billion euros was to the shipping sector and none of it to state entities.

France's largest bank, BNP Paribas (BNPP.PA), held around 700 million euros in Greek debt at the end of 2013, according to data provided by BNP. Most of the exposure was to corporate borrowers and none was to Greek state entities, the bank said.

BNP documents from end-2013 also show an additional 1.3 billion euros in exposure to Greek companies that are not tied to the Greek economic situation, such as shipping businesses.

Societe Generale (SOGN.PA) held 300 million euros in exposure to Greek corporate debt and had no sovereign exposure as of end-September, a spokeswoman for the bank said.

Of the total German exposure, 4.6 billion euros was to other banks, 3.6 billion euros to companies and private individuals, and 15.2 billion euros to state entities, the BdB said.

"The credit exposure of German banks in Greece is low," BdB head Thomas Kemmer said in a statement. "That's why, should it come to insolvency for Greece, the direct effects on German banks could be overcome.

"Even the contagion effects that would accompany an exit could be endured better than two or three years ago."

($1 = 0.8396 euros)