Fannie Mae and Freddie Mac saw modest gains in issuance of single-family mortgage-backed securities during July, with little sign of any expanded underwriting by sellers The two GSEs generated $83.29 billion of single-family MBS last month, up 7.2 percent from June. Fannie managed only a 1.9 percent gain for the month, while Freddie volume surged 13.8 percent, which gave the company an unusually high 47.0 percent share of the GSE market. A big part of Freddie’s sharp increase in issuance came from the $8.00 billion of seasoned loans the company securitized in July. That was nearly double the volume of Freddie mortgages more than three months old that were securitized in June. Some $1.92 billion of those loans were modified....