The Bundesbank said in a statement that the European Financial Stability Facility placed 1.431 billion ($1.8 billion) worth of three-month bills at a yield of minus 0.0217 percent.

A negative yield means that investors actually pay the EFSF to lend it money.

Demand for the issue was strong, with investors bidding for a total 4.594 billion euros worth of bonds, bringing the so-called cover ratio to 3.2.

Investors had already accepted negative interest rates on six-month bonds or bills issued by the EFSF last month.

The EFSF, which was established with a total lending capacity of 440 billion euros, is to be replaced eventually by a permanent rescue fund called the European Stability Mechanism, with 500 billion euros of firepower.

The ESM was to come into force on July 1, but it has suffered delays, notably owing to legal challenges in Germany.