Sonoma County Employees' Retirement Association, Santa Rosa, Calif., placed Grantham, Mayo, van Otterloo & Co. on watch for its $136 million global asset allocation portfolio, said Steven Marsh, senior investment officer.
The $2.8 billion pension fund's board approved the GMO action at its May 20 meeting. Mr. Marsh said the action was due to performance concerns. A spokesman for GMO declined to comment.
GMO is the sole manager of the pension fund's global asset allocation investment. Investment consultant Aon Hewitt Investment Consulting assisted.