Banks offered RON1.68 billion, but the ministry rejected all yields above 5.99% a year, central bank data showed.
The previous similar auction was held on March 26, when the ministry sold RON300 million in six-month paper at an annual yield of 5.06%, the lowest level on record for such a maturity.
The ministry plans to sell debt worth RON4.15 billion in October, slightly down from RON4.54 billion sold a month earlier. Additionally, the ministry will reopen a 2015 foreign currency bond on October 22 in a bid to raise EUR150 million.
So far in 2012, Romania sold RON44.44 billion in leu-denominated state notes and $2.25 billion in US dollar-denominated bonds.
Early September, the country raised another EUR750 million via a tap of its 6.5% June 2018-dated eurobond at an annual yield of 5.15%. (EUR1=RON4.5178)