Greek shares gained 5.63 percent in mid-day trading on Friday after a pre-dawn deal in Brussels to fight the eurozone debt crisis.
The Athex index stood at 610.84 points, led by a jump of 13.40 percent by banking shares as measured on the FTSEB index.
Among the chief Greek lenders, Eurobank rose by 16.77 percent, Alpha Bank picked up 15.45 percent, Piraeus Bank increased by 14.47 percent and National Bank was up 13.71 percent.
World stock markets surged overall and and the euro jumped against the dollar after an EU summit delivered surprise emergency measures.
The accord struck in Brussels paves the way for the eurozone's 500-billion-euro ($630 billion) bailout fund to recapitalise ailing banks directly, without passing through national budgets and adding to struggling countries' debt mountains.