First-lien mortgages held in bank and thrift portfolios increased by 4.1 percent at the end of the second quarter of 2012 compared with the same period in 2011, according to an Inside Nonconforming Markets analysis of bank call report data. The strong increase comes as banks actively sell poorly performing legacy mortgages and suggests that lenders have increased their non-agency portfolio originations. Of the 21 banks and thrifts with at least $10.0 billion in first-lien holdings as of the ... [Includes one data chart]