The Treasury sold 5 billion euros ($6.8 billion) at the top end of a target range of between 4 billion and 5 billion euros.
The 6-month bill sold 910 million euros at an average yield of 0.144 percent compared to 0.362 percent at the last auction of the same maturity May 13.
The bond was 5.1 times subscribed after 4 times previously.
The 12-month bill sold for an average yield of 0.384 percent compared to 0.598 percent previously in May. The Treasury sold 4.1 billion euros of the bill, though demand outstripped that by 2.0 times compared to 2.6 times at the previous auction.