ING Direct will pay 145 basis points over the 30-day bank bill swap rate on the top tranche of its latest residential mortgage-backed securities deal, which is the first by an Australian issuer this year.The issue, IDOL Trust Series 2012-1, was launched at A$500 million but closed yesterday at $800 million.The $744 million A1 tranche, which has a weighted average life of 3.2 years and expected ratings of AAA from Standard & Poor's and Moody's, is priced at 145 basis points over swap.Pricing on the $16 million AB tranche, the $20 million AC tranche and the $20 million B tranche (rated AA-) was not disclosed.The weighted average life on each of the lower tranches is 6.3 years.The Australian Office of Financial Management bought $200 million of A1 notes.ING Direct did its last RMBS deal in November, when it priced the $597 million A1 tranche, which had a term of 2.7 years, at 135 basis points over swap.