TMTPOST--China's Ministry of Finance said Thursday that it will auction 30 billion yuan (about US$ 4.21 billion) worth of book-entry discount treasury bonds on Friday. With a term of 91 days, the bonds will be sold at a discounted price and mature at par value. The price will be determined through a competitive tender on Friday, according to a statement released by the ministry. The bonds will become tradable on the securities market on August 7, the ministry said.