Standard & Poors Ratings Services, downgraded its credit ratings for four mortgage insurers late Tuesday citing a weaker than expected housing market and rising unemployment.

The insurers mentioned were MGIC Investment Corp., Old Republic International Corp., PMI Group Inc. and Radian Group Inc. The agency said further rating cuts were possible.

Standard & Poor's said it did not expect most companies to generate a profit from underwriting until 2010.

The downgrades reflect weaker-than-expected results for the fourth quarter of 2007 and the continued deterioration in key variables that influence claims for mortgage insurance, said S&P credit analyst James Brender said in a statement.

S&P said it expects home prices to drop by 20 percent from their highest levels in 2006 compared to previous estimates of an 11 percent drop in November. It also anticipates unemployment to rise to 5.8 percent in 2009. The rate is at 5.1 percent now.

MGIC's rating was cut to BBB from A-minus. Old Republic dropped to A from A-plus. PMI Group was now rated BBB from A. Radian was also down to BBB from A-minus.