Competitive pressures are beginning to catch up with the private mortgage insurance industry, squeezing the sector’s profitability and raising its risk profile, according to Wall Street analysts. Private MIs are caught between mortgage lenders that control the consumer relationship and the government-sponsored enterprises, with their charter advantages, said Ken Posner, a mortgage industry analyst at Morgan Stanley, in a new report. His firm downgraded its investment ratings for the PMI Group from Overweight to