Greece offered 10 billion euros ($13 billion) to buy back bonds issued earlier this year as the bailed-out nation attempts to cut a debt load that may threaten future international aid.

Greek bonds rallied after the so-called modified Dutch auction was announced today by the Athens-based Public Debt Management Agency. PDMA offered an average maximum purchase price for bonds maturing from 2023 to 2042 of 34.1 percent of face value and an average minimum of 32.1 percent, based on information in the statement. The offer runs until 5 p.m. London time on Dec. 7.

Success is crucial to releasing aid that's been frozen since June. The offer was part of a package of measures approved by euro-area finance ministers last week to cut the nation's debt to 124 percent of gross domestic product in 2020 from a projected 190 percent in 2014. The 10 billion-euro buyback may enable Greece to retire about 30 billion euros of debt, Citigroup strategist Valentin Marinov wrote in a comment.