Principal Financial Group Inc. has named Julia Lawler, currently senior vice president and chief investment officer, as senior vice president for investment services. Tim Dunbar, currently senior vice president for strategy and finance, will replace Lawler as senior vice president and chief investment officer. The changes, effective in January, reflect Principal's growth as a global investment manager and the need to manage its relationships with numerous external investment firms internationally, said Larry Zimpleman, Principal's chairman, president and CEO. In her new role, Lawler will oversee Principal's retirement and mutual fund investment services across all its outside asset managers, both domestically and globally. Lawler joined Principal in 1984 as a commercial real estate representative.