Kroger Co. replaced Chief Executive Officer Rodney McMullen following an investigation into his personal conduct, casting a shadow on the supermarket operator’s path forward following a failed deal and a string of management departures under the longtime leader.

The conduct is not related to financial performance, operations or reporting, and it did not involve any Kroger associates, the company said.

Under his leadership, Kroger has positioned itself as a formidable competitor to Walmart, Amazon, and other grocery giants.