ROME (Reuters) - Greek banking stocks surged on Thursday, rising over 20 percent amid market talk that secret opinion polls were showing that a government favorable to the international bailout agreement was likely to emerge after the June 17 election.

"The market sees that a pro-European government which will push ahead with reforms will be formed on Sunday," Panagiotis Kladis, an analyst at NBG Securities told Reuters.

Another broker said the market was trading the scenario that the radical leftist SYRIZA party, which opposes the European Union and International Monetary Fund-led bailout deal, would not gain enough support to form a government.

The main bank stocks index <.FTATBNK> stood 20.08 percent higher at 218.2 at 0615 EDT, outperforming the broader market <.ATG>, which was up 6.85 percent.

Greek law forbids the publication of opinion polls in the two weeks before elections.

(Reporting by Lefteris Papadimas and George Georgiopoulos)