While Fannie Mae issuance declined in August, the government-sponsored enterprise’s gross mortgage portfolio increased 3.8% from a year ago. The Fannie Mae gross mortgage portfolio reached $809.1 billion in August, up 3.8% from $779.4 billion a year ago. It did drop at a compound annualized rate of 4.1% in August. Fannie Mae reported $47.9 billion of total issuance of mortgage-backed securities in August, down 22.7% from a year ago but a 12.2% increase from the previous month. Its MBS issuance peaked in June 2009 at more than $130 billion. The serious delinquency rate in the Fannie Mae portfolio dropped for the fifth month in a row to 4.82% in July, the latest month of available data, from 4.99% in June. It’s still 65 basis points above the rate last year. Today, the House Committee on Financial Services is holding a hearing on the future of the GSEs. Michael Bodaken, president of the National Housing Trust will say in written testimony released yesterday that the serious delinquency rate on Fannie and Freddie Mac single-family mortgages rose from 3% in 2005 to 11.5% in 2009. Write to Jon Prior.