Mr Clitheroe moves into the executive position after being elected chairman at a board meeting on 26 November 2014.
According to a statement on the ASX, Mr Heap's departure comes after a strategic review that will see AWI focus on its digital wealth businesses InvestSMART, YourShare and Intelligent Investor.
Mr Clitheroe said the changes would allow AWI to streamline its business "and align its cost structure with the size of the company".
"Ben has played a key role in setting the vision for AWI and I anticipate the results over coming years will reflect this work, together with the efforts of the management, staff and board," Mr Clitheroe said.
"I would like to thank Ben for his dedication to AWI, as the company's chief executive and managing director, through a challenging period and wish him every success in the future," he said.
