The appointment is effective immediately. Previous CEO Len Brennan will serve as chairman through the end of 2017, after which point he will become a strategic adviser to the firm; plans beyond that are not known, Mr. Brebbia said. Ms. Seitz will become chairman of the board effective Jan. 1, 2018.
Ms. Seitz was previously head of investment management at William Blair & Co. Spokesman Tony Zimmer did not have any information regarding Ms. Seitz's position.
William Blair had $65 billion in worldwide assets under management as of Dec. 31, according to Pensions & Investments data.
"We are excited to welcome Michelle as Russell Investments' new CEO, and believe that her forward-looking leadership will help propel the firm into a new phase of evolution and growth that will benefit clients and associates alike," said Todd R. Crockett, managing director, TA Associates, in a Russell news release. TA Associates, along with Reverence Capital Partners, acquired Russell Investments in 2016.
Russell Investments had $2.4 trillion in assets under advisement as of June 30, 2016, and $258 billion in worldwide assets under management as of Dec. 31, according to P&I data.