Ireland's debt agency NTMA on Thursday sold treasury bonds at a negative yield for the first time ever.

The NTMA sold 500 million euros (570 million U.S. dollars) worth of a medium-term treasury bond, maturing in 2022, at a yield of -0.009 percent.

The agency also sold 250 million euros of a treasury bond maturing in 2045 at a yield of 1.953 percent.

Thursday's sales were the country's fifth dual bond auction of this year.

The NTMA returned to dual auctions in February this year for the first time since 2010.

With the completion of Thursday's auction, the NTMA has issued 9.5 billion euro benchmark bonds.

Early this year, the agency said it will issue between 9 and 13 billion euros of long-term bonds this year.

In Ireland, the NTMA is responsible for borrowing on behalf of the government and managing the national debt.

Last year, the agency raised 8.25 billion euros in funding. (1 euro = 1.14 U.S. dollars)