After launching a A$500 million prime RMBS issue on Tuesday, National Australia Bank upsized and priced the issue yesterday. The RMBS issue, via National RMBS Trust 2012-2, was increased to A$1.0 billion.This issue follows a A$5.8 billion internal securitisation undertaken by the bank in September.The latest issue includes A$800 of Class A1 notes that have a weighted average life of 3.22 years and were priced at 110 basis points over bank bills, and £85 million (A$130 million) of Class A2 notes with a weighted average life  of 3.01 years. The pricing on the Class A1 notes is the tightest seen on comparable RMBS since July 2011. At that time, Bendigo and Adelaide Bank sold A$500 million of prime RMBS with a weighted average life of 2.9 years, at 105 bps over bank bills.The Class A2 notes priced at 60 bps over Libor and are structured with a three-year soft bullet maturity. The notes will be redeemed via the subsequent sale of Class A2R pass-through notes.The Class A1 and A2 notes have provisional AAA ratings from Fitch Ratings and Standard & Poor's.Pricing was not disclosed on the A$50 million of Class B notes or the A$20 million of Class C notes. The former have a provisional BBB rating from S&P and the latter are not rated. The transaction has a final maturity date of June 20, 2044.