Shell Oil Co., Houston, hired three large-cap equity enhanced index managers as part of an initiative to help lower and more accurately predict risk, said Janet Handley, senior staff investment specialist for the $6.5 billion defined benefit plan. Hired were Chicago Equity Partners; Westpeak; and Geewax, Terker. Chicago Equity Partners will manage approximately $100 million. Ms. Handley would not reveal the size of the other firms portfolios. The funding came from a reallocation, but Ms. Handley wouldnt say if any managers were terminated.