The private mortgage conduit business surged to a record $231.7 billion in mortgage securities issuance during the third quarter of 2004 and has become nearly as big as the combined Fannie Mae, Freddie Mac and Ginnie Mae market. A new Inside Mortgage Finance ranking and analysis reveals that private conduits accounted for 49.3 percent of total mortgage securities issuance during the third quarter. While the private conduit sector grew 15.0 percent from the second quarter…