Originations of interest-only mortgages declined by 6.6 percent on a sequential basis in the third quarter among a group of lenders surveyed by Inside Nonconforming Markets. Total first-lien mortgage originations declined by 2.2 percent in that span. Fifteen lenders originated $4.74 billion of IOs in the third quarter. Some 33 percent of the lenders managed to increase their IO production on a quarterly basis, with large gains at Citadel Servicing, PNC Mortgage and ... [Includes one data chart]