Garrett Walls was named CEO, institutional Americas, at JPMorgan Asset Management. Mr. Walls succeeds Eve Guernsey, who was promoted to chief executive of the Americas in July. Mr. Walls was head of institutional sales and service and oversaw marketing in the Western region. That region has been consolidated with the Midwest under the supervision of Michael Davis. Officials at JPMorgan plan to hire a salesman to replace Mr. Walls in San Francisco.