The $4.3 billion New Mexico Public Employees Retirement Association, Santa Fe, replaced a bond manager and retained three incumbents following a search. BlackRock Financial was hired to run a $490 million mortgage-backed securities portfolio, replacing Smith Breeden Associates. Jeffrey W. States, director-investments, said the change was not performance-related. Incumbents retained were Nicholas-Applegate for a $390 million active long-term bond portfolio; BZW for a $414 million core fixed-income portfolio; and Putnam Investments for a $450 million short/intermediate fixed-income portfolio. Wilshire assisted.