Hefty secondary marketing margins continued to boost mortgage banking income at a faster pace than total sales activity during the third quarter of 2012, according to a new Inside Mortgage Trends analysis of bank call report data. Banks and thrifts reported a total of $401.6 billion in sales of single-family mortgages during the third quarter, a hefty 11.5 percent increase from the previous three-month period. But mortgage banking income – which is derived largely from ... [Includes one data chart]