Private mortgage insurers represented by the Mortgage Insurance Companies of America wrote $4.9 billion in new business in July even as some of the industry's players struggled with falling stock prices and uncertainty about future liquidity levels. Still, MICA reported its member companies – including Genworth Mortgage (GNW), Mortgage Guaranty Insurance Corp. (MTG), PMI Mortgage Insurance (PMI), Radian Guaranty (RDN), and Republic Mortgage Insurance Co. (ORI) – had $601.7 billion in primary insurance in force last month. That is down from $606.3 billion in June. Defaults outpaced loan cures in July with MICA reporting that insurers under its umbrella had 48,758 loan defaults insured by the industry and 35,905 cures. In July, 22,917 borrowers used private mortgage insurance to buy or refinance a home. Member companies received more than 26,000 applications. The month of August turned into a turbulent period for some mortgage insurers. In August, The PMI Group ended up under the direct supervision of its chief regulator, the Arizona Department of Insurance. Regulators forced the insurer to halt the writing of new business. PMI's troubles prompted one analyst to predict the insurer will lose market share to its competitors. Volatility in the stock market in early August also riled mortgage insurance stocks with a few of the companies experiencing 20 to 50% stock price declines within a relatively short period. Write to: Kerri Panchuk.