Ohio Public Employees Retirement System, Columbus, is conducting a shortlist search for a high-yield bond manager; the size of the portfolio has not been determined, said Christopher Federer, spokesman. Ennis Knupp is assisting; a selection is expected early next year. The $52 billion system's other high-yield managers are Shenkman Capital, which runs $397 million, and W.R. Huff, which handles $258 million. Officials are reviewing whether the portfolios will be trimmed, Mr. Federer said. "We feel another manager is necessary to diversify the investment style mix within our high-yield allocation," he said.