Brian Roberts was named investment officer, private equity, at the $84.8 billion Washington State Investment Board, Olympia, confirmed spokeswoman Liz Mendizabal in an e-mail. He started Monday. Mr. Roberts will monitor the boards existing private equity relationships and perform due diligence on new opportunities globally. He replaced Sam Green, who was named private equity investment officer at the Oregon State Treasurers Office of Investment, which oversees the $64.9 billion Oregon Public Employees Retirement Fund, both in Salem. Mr. Roberts was director of transition management at Russell Investments. Spokesman Steve Claiborne did not have information about a replacement by press time.