Katie Rooney is just about a month into her new role at insurance brokerage Aon Corp. as chief operating officer for global finance and shared services. It's a quick move forward for the 32-year-old Chicago area native, who previously served as Aon's assistant treasurer for corporate finance/mergers and acquisitions.

Rooney attended the University of Michigan and then spent the first nine years of her career at Morgan Stanley. Her last position was vice president in investment banking in the healthcare group, where she worked with medical technology companies on all aspects of their debt, equity and M&A activity.

A year after joining Chicago-based Aon in 2009, Rooney led a team that managed the financing for Aon Consulting's $4.9 billion acquisition of Hewitt Associates, the largest in Aon's history. She also helped implement a new $2 billion share buyback program and was instrumental in managing capital structure, including optimizing the maturity, yield and refinancing risk of more than $4 billion in corporate debt.