Investing.com -- Kroger shares opened lower on Monday after the company announced the resignation of Chairman and CEO Rodney McMullen following a Board investigation into his personal conduct.

In a statement, Kroger (NYSE: KR) said McMullen’s behavior, while unrelated to the company’s financial performance or operations, was found to be inconsistent with its Policy on Business Ethics.

The Board learned of the matter on February 21, stating that it retained outside counsel to conduct an independent investigation overseen by a special committee.

To ensure continuity, Kroger has appointed Lead Director Ronald "Ron" Sargent as Chairman and interim CEO, effective immediately.

"As interim CEO, I am committed to working alongside our proven and experienced management team and dedicated associates to ensure Kroger continues providing exceptional value for our customers," Sargent said.

Sargent, who has served on Kroger’s board since 2006 and as lead independent director since 2017, brings extensive retail leadership experience.

He previously spent over a decade at Kroger early in his career and later served as Chairman and CEO of Staples from 2002 to 2016. In connection with his new role, he will step down from certain board committee positions.

Kroger added that it has formed a search committee and engaged an executive search firm to identify Kroger’s next CEO. In the meantime, Mark Sutton has been appointed lead independent director.

Despite the leadership shakeup, Kroger reaffirmed its financial outlook, expecting full-year identical sales without fuel to be at the high end of its guidance and adjusted earnings per share to slightly exceed expectations.