Robertson will stand down as the asset manager’s head at the end of 2013, after deciding to retire because of health issues.
Armour, who has led Invesco’s global institutional business since 2007, will take over as head of Invesco Perpetual’s Europe, Middle East and Africa region upon Robertson’s retirement.
Armour has been in the investment management industry since the early 1980s and joined Invesco in September 2002 as chief executive of Invesco Australia. Before this, he was chief investment officer at ANZ Bank and held senior leadership roles in the fund management business in Australia and Hong Kong.
Invesco Perpetual said: “Mark will work with James to ensure a smooth, orderly transition of responsibilities. Over the long term, he will work with the leadership team to take the business forward and ensure our continued growth and success by delivering for our clients.
“Mark has long-standing and good relationships with the senior management team here, and they are looking forward to working together to build on the business’ success and strong market position. We anticipate this transition will have no impact on clients.”
Robertson joined Invesco Perpetual in 1993 as director for finance and corporate development in its global division. After holding other senior roles in the group, he was appointed chief executive in 2008.