Freddie Mac’s ($0.00 0%) volume of purchased refinanced loans grew in August as the mortgage giant’s single-family delinquencies continued to swell.

Freddie reported $47.8bn in issuances for August, up from $44bn in July and almost doubling the $25.7bn in August of 2008.

The total mortgage portfolio also showed an increase at an annualized rate of 3.7% in August. Refinanced mortgage purchases made up $35.6bn, a slight increase from $34.1bn in July, according to Freddie’s monthly volume summary.

The net amount of mortgage purchases or sales agreements made for Freddie’s mortgage-related investments portfolio totaled $12.1bn, a slight bump from $11bn during July.

But 90-day single-family delinquencies stayed continued to increase for Freddie. In August, the portfolio had a 3.13% delinquency rate, an increase from 2.95% in July and 1.11% in August of 2008. Every month between August of last year and the latest monthly summary showed an increase in delinquencies.

But multifamily loans were 0.1% delinquent for August, slightly down from 0.11% in July.

Write to Jon Prior.