Thanks to the Federal Reserves aggressive support for the agency mortgage market and continuing strength in the refinance program for underwater Fannie Mae and Freddie Mac borrowers, mortgage refi activity has accounted for 73.1 percent of 2012s surging production volume. But home-purchase lending started to regain some market share during the third quarter of 2012, according to a new Inside Mortgage Finance ranking and analysis. An estimated $143 billion of home-purchase mortgages were originated during the third quarter, up 10.9 percent from the previous three-month period. By comparison, refinance production was up just 2.8 percent from the second quarter. The purchase-mortgage sector still has...[Includes three data charts]