* Greek borrowing costs rise
* Athens' banking shares touch record lows
ATHENS/LONDON, Feb 8 (Reuters) - Greece's main equity index fell to its lowest level in more than 25 years, with bank shares touching record lows, driven by political uncertainty and concerns about Europe's financial sector.
Athens' benchmark ATG equity index was down 8 percent on Monday, at its lowest level since at least 1991.
The Athens Stock Exchange FTSE Banks Index also fell 26 percent to touch record lows, with shares in major lender National Bank of Greece falling 28.6 percent.
Greece's finance minister said on Monday that the country expected the review of its bailout performance to resume next week and conclude two weeks later.
However, Greek borrowing costs rose on the back of uncertainty that a bailout review by the country's lenders could drag on due to resistance to planned pension and tax reforms, which also hit the Athens stock market.
"The market is pricing in financial and political instability and delays in the review," said Manos Hatzidakis, an analyst at Beta Securities.
Banking shares across Europe were also hit as concerns over global growth and the health of Europe's financial sector pushed investors into safe-haven assets.
The cost of insuring financials' subordinated debt also hit its highest level since April 2013, according to Markit data.
Mission chiefs of Greece's lenders, the European Commission, the International Monetary Fund, the European Central Bank and EU's bailout fund wrapped up a first week of talks in Athens on Friday. They were expected to return to Greece around Feb. 15.
Greece has promised to cut pension spending by 1 percent of GDP, or 1.8 billion euros, this year. To protect pensioners whose benefits have been cut 11 times already since 2010, the government has proposed to increase social security contributions by employees and employers.
(Reporting by Lefteris Papadimas and Angeliki Koutantou; Additional reporting by Sudip Kar-Gupta and John Geddie; Editing by Alexander Smith)