NAB hybrid swamped in US 21 September 2009 4:36PM Philip Bayley The other big issue of the week was National Australia Bank's US$600 million Tier 1 hybrid issue. Originally pitched as a US$500 million issue paying 520 bps over US Treasuries, a US$5 billion order book (as reported by Reuters) saw the issue size edged up and the coupon reduced to Treasuries plus 494 bps.The hybrid securities are perpetual with the coupon reset every seven years and stepping up to Treasuries plus 740 bps after year 14, if not called.