Sellers of credit-default swaps on Greece will have to pay as much as $2.5 billion to settle contracts triggered by the nation's debt restructuring.

The settlement was determined after dealers agreed a final value for Greek bonds of 21.5 percent of face value at an auction, according to administrators Markit Group Ltd. and Creditex Group Inc., and is in line with where the notes have been trading.

Greek credit-default swaps are being settled after investors were forced to exchange their bonds at a loss in the biggest ever debt restructuring. The auction ends more than two years of speculation over whether the derivatives are reliable for insuring sovereign debt after European policy makers sought to prevent payouts on concern they'd worsen the region's crisis.