The amount of monthly mortgages purchased for securitization by Freddie Mac fell nearly 31% in March to $26.9 billion. The government-sponsored enterprise reported its total mortgage portfolio decreased at an annualized rate of 4.7% during the month to $2.14 trillion. Monthly purchases and issuances have been steadily decreasing since December and are now down 46% from then, which represented the peak of 2010. Year-to-date, Freddie Mac has purchased and issued $104.7 billion in mortgage guarantees. The drop comes amid heated debate on how and when to reduce Fannie Mae and Freddie Mac's presence in the mortgage marketplace. Under Dodd-Frank, the GSEs need to reduce market share, but there is no consensus on how to accomplish the task. Republicans approved eight bills in March calling for a rapid end to government support for the companies, including one bill that prevents the GSEs from increasing the size of their portfolio. In February, the Treasury Department proposed three options for winding down the mortgage giants. The single-family refinance-loan purchase and guarantee volume at Freddie Mac hit $19.4 billion in March, accounting for 72% of its mortgage purchases and issuances. Meanwhile, the aggregate unpaid principal balance of the GSE's mortgage-related investment portfolio fell by about $4.1 billion. Freddie's mortgage-related securities and other guarantee commitments also declined in March dropping 5.3% from a year earlier. Freddie's single-family delinquency rate fell to 3.63% last month, while the multifamily delinquency rate remained flat at 0.36%. Write to Christine Ricciardi. Follow her on Twitter @HWnewbieCR.