Romer-Lee was managing director of Morningstar's investment consulting operations in Europe, while Whittingham served as managing director of Morningstar OBSR in the UK and Ireland.

Until the company appoints new managers, Geoff Balzano, chief executive of Morningstar UK, will lead the Morningstar OBSR business operations, while Hal Ratner, chief investment officer for Morningstar Investment Management in Europe, will lead the European business operations outside of the UK.

Romer-Lee and Whittingham joined the firm when it acquired OBSR (Old Broad Street Research) in early 2010. Romer-Lee was a co-founder of OBSR and Whittingham served as its development director.

“Now that the OBSR businesses have been integrated into Morningstar, Nigel and I recognise that it is time for us to take a break," Romer-Lee said. "We will continue to focus on client needs during this time of transition."

Morningstar UK is a subsidiary of Morningstar, a provider of independent investment research in North America, Europe, Australia and Asia. The firm has over $186 billion in assets under advisement and management as at end-June.