Even as the Obama Administration's Making Home Affordable initiatives began taking effect, one of the government-sponsored mortgage giants saw its April portfolio shrink from year-ago levels as its monthly purchases and issuance fell 32.5%. Government-sponsored enterprise (GSE) Freddie Mac (FRE) saw its mortgage portfolio decrease at an annualized rate of 8.1% in April, according to the monthly volume summary released today. Freddie's total mortgage-related purchases and issuance fell to $58.1bn in April from $86.1bn in March. It sold $20.2bn in April from its total mortgage portfolio. The declines in mortgage activity at the GSE came even as it began purchasing refinance loans through the Administration's new housing program. Freddie purchased $43.3bn of refinance loans in the month through the Making Home Affordable Program (MHA Program). Officials from the GSE said refinance activity will likely remain high in coming reports as Freddie continues to purchase refinance loans through the program. Despite the future outlook on refinance-related activity, Freddie's April portfolio contracted, also bringing down the unpaid principal balance (UPB). The aggregate UPB of Freddie's mortgage-related investments portfolio decreased to $830.3bn at month-end. The GSE entered into $956m of mortgage purchase and sales agreements for its mortgage-related investments portfolio, down from $15.8bn in March. As Freddie's portfolio contracts, the deteriorating performance of its mortgages only becomes clearer, as the delinquency rate continues to rise each month for the past 12 months. The total delinquency rate among Freddie's single-family mortgages increased to 2.44% from 2.29% last month, according to Freddie's report. The rate is up from 0.81% in April of '08. "Our temporary suspension of foreclosure transfers, which expired on March 6, contributed to the increase in our single-family delinquency rates," Freddie officials say in a media statement today. "We are currently assessing the impact on our delinquency rates of the suspension of foreclosure transfers that began on March 7 for loans eligible for modification under the MHA Program." Write to Diana Golobay. Disclosure: The author held no relevant investment positions when this story was published. Indirect holdings may exist via mutual fund investments.