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.

Kroger CEO Rodney McMullen resigned from his post on Monday, weeks after a merger with Albertsons fell through.

The grocery chain said it had investigated its chief executive, Rodney McMullen, and found that his actions were “inconsistent” with its business ethics policy.