Greece's debt management agency says it is issuing more of an existing 20-year bond as it seeks to raise up to 1 billion euros ($1.35 billion).

The bond, with a 5.9 percent coupon, is due to mature on 22 Oct. 2022, the debt management agency said Tuesday.

The reopening of the old bond issue comes a day after Greece raised 5 billion euros with a seven-year bond issue, in a crucial first borrowing test after the euro zone unveiled a rescue last week to help Athens cope with its acute debt crisis.

Monday's bonds were sold with a coupon of 5.9 percent. The high yield comes before April and May deadlines to refinance about 20 billion euros in debt, with total borrowing needs at 54 billion euros ($72 billion) this year.