Standard & Poor’s was the most active rating service in the MBS and ABS markets during the first half of 2009, although the company isn’t as dominant as it has been in the past. S&P rated 57.8 percent of new non-agency MBS issued with ratings during the first six months of the year, edging past Fitch Ratings as the top player in the market. Although S&P’s rating... [Includes two charts]