The Ministry of Finance (MOF) announced Friday that it will issue 20 billion yuan (3.23 billion U.S. dollars) in 50-year book-entry treasury bonds. The issuance marks the ministry\'s tenth issuance of book-entry treasury bonds this year, according to a statement posted on the MOF website. The interest rate for the bonds is fixed at 4.24 percent. Interest will be paid every half year on May 20 and Nov. 20 annually, while the last interest and the principal will both be paid upon maturity on May 20, 2063. The bonds will be sold from May 20 to 22 and become tradable on exchange markets starting on May 24, according to the statement.