The recommendation made by the system's investment committee was approved at a board meeting Tuesday.
Acadian manages about $1 billion for Mississippi PERS in global equity; it's the only strategy for which the firm was on the watchlist, according to Robert Clark, the system's CIO.
The manager was taken off watch because the firm outperformed its benchmark on a rolling three-year relative performance basis, the spokeswoman said.
Acadian was put on watch in June 2018 because of underperformance for four rolling three-year periods.
Acadian did not respond to an email requesting comment.
As of Oct. 31, the pension fund had $36.8 billion in assets.