Previously, Walker was chief financial officer for Barclays Capital's Americas business. In his new roles, Walker will be based in New York and will report to Gary Bullock, the firm's head of global investment banking operations.
Walker's investment banking role is a newly created position, which in conjunction with his responsibilities for the bank's OTC business, places him in charge of most of the firm's investment banking operations globally.
As global head of OTC operations, Walker will be responsible for the bank's OTC derivatives, foreign exchange, loans and commodities businesses. The previous OTC head, Stefano Toffolo, has been appointed global head of cash operations, another newly created position.
Before joining Barclays Capital, Walker spent 13 years at Merrill Lynch, where he held numerous roles, including head of global debt and derivatives operations, head of European derivatives operations, and chief financial officer of global markets and investment banking. Before joining Merrill Lynch, Walker spent eight years at Morgan Stanley in London and Tokyo.