Kroll Bond Rating Agency Inc., the ratings company started by private investigator Jules Kroll, hired four analysts from Morningstar Inc. (MORN) for its commercial- mortgage backed securities group.

The company named Steve Kuritz as senior director, Laura Shannon and Bill Peterson as directors, and Mike Haas as an associate, according to Eric Thompson, who heads the business at Kroll. The four will work on a surveillance team and report to Thompson from a new office in Horsham, Pennsylvania, the same town where Morningstar houses its credits-ratings business.

Kroll garnered more than 40 percent market share in rating debt backed by offices, hotels and shopping malls last year, after entering the sector in July 2011, according to Commercial Mortgage Alert, an industry newsletter.  Kroll graded $21.2 billion of debt, up from $2.8 billion in 2011, putting the New York-based company behind Moody’s Investors Service and Fitch Ratings in market share.

Morningstar’s share of the rated CMBS market declined to 18.7 percent from 23.7 percent, grading $9.85 billion last year, according to the newsletter. The mutual-fund data company, owned by billionaire Joe Mansueto, bought credit-rater Realpoint LLC in 2010, which has the Nationally Recognized Statistical Rating Organization designation needed for investors required to buy debt that meets certain ratings criteria.  Realpoint’s founder, Robert Dobilas, left in November.   Shawn Malayter, a Morningstar spokesman, confirmed the departures and declined to comment further.

Jules Kroll, 71, bought rating-firm Lace Financial in 2010. Thompson was previously a managing director in the CMBS group at Standard & Poor’s and reports to structured finance leader Kim Diamond, former head of CMBS at S&P.