Private mortgage insurers appear to be holding on to the gains in market share they began to accumulate in the middle of last year, according to a new Inside Mortgage Finance analysis. An estimated $108.61 billion of home mortgages originated in the first quarter of this year carried primary mortgage insurance, an increase of 9.4 percent from the previous quarter. That compared to a 3.8 percent drop in total single-family mortgage originations over that period. The apparent jump in primary MI market penetration to 28.2 percent is skewed somewhat by the process for...(Includes two data charts)