St. Louis Public School Retirement System will add about $19.2 million to a Mellon domestic core fixed-income index fund benchmarked to the Lehman Aggregate index, according to recently released minutes from a Nov. 6 special meeting. The system had $14.7 million in the Mellon fund as of Dec. 31. Funding will come from terminating a $19.2 million domestic core bond portfolio managed by MDL Capital Management. The termination was recommended by investment consultant NEPC owing to recent findings in a legal action brought against the firms owner and chief executive officer, Mark Lay, according to the minutes. Neither Mr. Lay nor Andrew Clark, executive director of the $1.1 billion fund, returned phone calls seeking comment.