Kiwibank is looking to lift its capital base by more than a quarter with the sale, for the first time, of hybrid securities.The move is significant in that this is the first time since the formation of the bank in late 2001 that Kiwibank has looked for capital from any entity other than its owner New Zealand Post, which in turn is owned by the New Zealand government.NZ Post yesterday incorporated two companies with the aim of using one of them to issue preference shares that will be used to boost Kiwibank's tier one capital.The company, called Kiwi Capital Securities, is planning to make an offer to the public of up to NZ$150 million perpetual callable non-cumulative preference shares, including oversubscriptions of up to NZ$50 million. The instrument will be called Kiwi Income Securities and is expected to open for bids from investors in early April.Like similar hybrid securities of other banks, the shares will not entitle holders to any voting rights in Kiwibank, and only limited voting rights in Kiwi Capital Securities.Kiwi Capital Securities is owned by Kiwi Capital Management, which in turn is owned by Kiwi Group Holdings, a subsidiary of NZ Post.  The shares will have no maturity date and may be called on the fifth and tenth anniversary of their issue date and quarterly thereafter, and in certain other circumstances.The company will announce the minimum dividend rate prior to the offer, which will be fixed for the initial five years. After that period, they will be reset for subsequent five-year terms at the margin plus swap rate applying at the time. Kiwibank had tier one capital of NZ$415 million as of December 2009, consisting mainly of paid up share capital of NZ$310 million.  The tier one capital as a ratio of total risk-weighted exposure was 7.2 per cent, down from 7.7 per cent the year before.  The ratio fell despite an increase of NZ$35 million in share capital and a NZ$86 million boost from revenue and similar reserves.The minimum tier one capital ratio under the Crown Wholesale Guarantee is six per cent, though the guarantee itself is due to expire next month.