Bank of New Zealand yesterday commenced marketing of its third covered bond, through its London branch. BNZ will denominate the five-year bond, secured by NZ dollar mortgages, in Australian dollars.The size of the bond was not clear last night, although afr.com reported price talk in a range from 88 to 90 basis points over swap.ANZ National is also marketing its debut covered bond, which is expected to be priced at around €1.5 billion.