ASB’s Vittoria Shortt sees economic momentum returning in coming months. (Image: Supplied)ASB has posted a lower annual after-tax profit, with its $135.6 million class action settlement seeing operating expenses rise amid a year with uneven economic forces. The bank posted a net profit after tax of $1.4 billion for the year to June 30, down from $1.45b a year earlier. This was achieved on net interest income of $3.3b, from $3.1b.Net interest margin (NIM), a key profitability gauge among banks, was 2.3%, or down three basis points from 2.27% a year ago. “[The] economic recovery has been very stop-start.