Mortgage insurer Radian Guaranty (RDN) wrote $2 billion in new primary mortgage insurance in January, while watching its inventory of delinquent loans edge downward.

The company ended the month with 109,803 delinquent loans in its inventory of insured mortgages, compared to 110,861 delinquencies in December 2011. New business, however, fell in January. Its $2 billion in new primary insurance was down from $2.3 billion in December.

For the 31-day period, the Philadelphia-based insurer reported 7,192 new delinquencies, compared to 8,999 in December. In January, the company's number of delinquent loans was impacted by 6,138 cures, 1,118 paids and 994 rescissions and denials.

Radian, like most mortgage insurers, is a on a quest to raise capital to compete in a market riddled with uncertainty and anemic home lending. The insurer announced in January a deal with subsidiaries of Assured Guaranty in which Radian would commute a $12.9 billion portfolio that it reinsures for the muni bond insurer. A commutation allows a reinsurer to end obligations to another insurer by paying a lump sum that ends the reinsurer's future insurance liabilities on the assets.

Radian also said it would raise $91 million by selling its muni bond insurance unit — Municipal Infrastructure Assurance Corp. — to Assured Guaranty.