Firms participating in the Public-Private Investment Program with a focus on non-agency mortgage-backed securities all took losses in the fourth quarter of 2011 compared with the previous quarter, according to an analysis by Inside Nonconforming Markets. The Oaktree PPIP Fund which only invests in commercial MBS was the only public-private investment fund to increase its net internal rate of return since inception in the fourth quarter of 2011, Treasury Department data show. The Treasury cautioned that it is ... [Includes one data chart]