Commonwealth Bank sold A$1.25 billion of four-year floating rate notes yesterday, Bloomberg reports. This is the first senior bank bond issue in almost two months.CBA sold the July 2017 bonds to yield 85 basis points more than the bank bill swap rate.Bank of Queensland was the last bank to sell bonds, on May 23. And National Australia Bank was the last big bank into the market, on May 16.Separately, CBA's New Zealand subsidiary ASB has joined Westpac NZ in a freshly re-opened local debt market with an issue of NZ$525 million of five-year unsecured bonds priced at the bottom of the indicative range. The amount raised was more than double the originally indicated size and its margin to underlying bank bill rates was priced 11 basis points lower than the last five-year bond issued by a New Zealand bank in March. The falling margins for such floating rate note issues are helping New Zealand banks offset a rise in longer term wholesale interest rates over the last two months.ASB said the issue of fixed and floating rate notes were priced at a margin of 110 basis points over 90 day bills, which was at the bottom of an indicated range of 110-115 basis points.The amount raised was increased from an originally indicated issue size of NZ$100 million to NZ$275 million.Westpac NZ's issue of NZ$385 million of three year floating rate notes at 75 basis points over swap last week was also set at the bottom of the indicated range and amount raised was at the top half of the indicated range.  Westpac NZ said the margin was the lowest for a three year bank issue since the Global Financial Crisis.The market for bond issues by New Zealand's big four banks had been closed since March, when BNZ issued NZ$250 million of 5 year floating rate notes at 121 basis points over swaps. Up to NZ$7 billion of New Zealand bank bonds need to be rolled over in the next 12 months.