Freddie Mac (FRE) purchased fewer refinanced loans in September as the mortgage giant’s single-family delinquency rate continued its steady climb. Freddie issuance totaled $32.9bn in September, down from $47.8bn in August and up from $27.2bn in September 2008, according to the agency’s monthly volume summary. The total mortgage portfolio increased at an annualized rate of 0.8% in September. Refinance mortgage purchases totaled $21.4bn in the same month, dropping nearly 40% from $35.6bn in August. The net amount of mortgage purchases or sales agreements made for Freddie’s mortgage-related investments portfolio reached $4.6bn, falling from $12.1bn in August. The 90-day single-family delinquencies increased again in September to 3.33% from 3.13% in August. Delinquencies swelled from 1.22% in September 2008 and have increased every month since by an average of 17 basis points. Write to Jon Prior.