Private mortgage insurer MGIC Investment Corp. (MTG) held 213,860 delinquent loans within its inventory at the end of January, down slightly from 214,724 delinquent loans at the onset of the month. In just the month of January, the Milwaukee-based firm wrote $1.2 billion in primary new insurance. The slight improvement in delinquent loan inventory comes on the heels of MGIC reporting a net loss for the fourth quarter of 2010. The private mortgage insurer posted a net loss for 4Q 2010 of $186.7 million, compared to a net loss of $280.1 million for the same quarter a year earlier. Loss per share was 93 cents for the quarter, compared to a loss per share of $2.25 for the same quarter in 2009. In 4Q of 2010, the company wrote $4.2 billion in new mortgage insurance, which was substantially higher than the $3 billion written in 4Q of 2009. Write to Kerri Panchuk.