PMI Group (PMI) narrowed its first-quarter loss by 19.2%, as the company substantially increased the level of mortgage insurance written. The Walnut Creek, Calif.-based company reported a loss of $126.8 million, or 79 cents a share, for the three months ended March 31 compared to almost $157 million, or $1.90 a share, a year earlier. Revenue increased 11.3% to $160 million from $143.7 million in the first quarter of 2010. About $135.5 million in revenue was attributable to mortgage insurance operations. However $271.4 million in losses and expenses negated any profit for that sector, resulting in a loss of $136.3 million for the quarter, which is 12% wider than the loss of $121.8 million attributable to mortgage insurance operations a year earlier. Mortgage insurance contracts written in the first quarter rose 52.5% to $1.47 billion from $964 million the year prior. Primary new risk written during the period was $352 million up from $214 million. Total primary insurance in force at the end of the period totaled $99.34 billion, according to PMI, while primary risk in force was $24.29 billion. The mortgage insurer's average loan size was $162,000 for these operations. PMI reported its primary default rate at 19.53%, and its loan loss reserves at $2.86 billion. As of March 31, PMI held total assets of $4.09 billion with $3.68 billion in mortgage insurance assets. Write to Christine Ricciardi. Follow her on Twitter @HWnewbieCR.