1.   Prove that the duration of a perpetual bond is equal to the inverse of the current yield on the bond.

2.   It is a perpetual bond with coupon d and a required rate of return r B.

3.   Banking gained for a second day after the finance and justice ministries agreed that banks may sell perpetual bonds --bonds with no maturity dates.

4.   Japanese stocks rose, led by banks on expectations the government will let them sell perpetual bonds and that commercial land prices may have bottomed out.

5.   The finance and justice ministries agreed to allow banks to issue perpetual bonds, or bonds with no maturity date, the Nihon Keizai newspaper reported.

6.   The finance and justice ministries have agreed to allow banks to issue perpetual bonds, or bonds with no maturity date, the Nihon Keizai newspaper reported.