Private mortgage insurer Radian Group Inc. (RDN) saw its delinquent loan inventory grow in December, although it remains down from last year.

The Philadelphia-based company recorded 93,169 delinquent loans by the end of December, up from 92,770 delinquencies at the beginning of the month and down from 110,861 delinquencies a year earlier, according to a securities filing. 

The private mortgage insurer also wrote more new insurance in 2012, with $37.1 billion in new business. That compares to a $15.5 billion book of new business in 2011.