By Stuart Condie

SYDNEY--WiseTech Global Chairman Richard White has stepped down from his post, citing concerns that media reports regarding his personal life had the potential to encourage short-selling activity.

The logistics-software provider said Tuesday that it has appointed Raelene Murphy as independent board chair. White, the company's co-founder and largest shareholder, will remain as an executive director and chief innovation officer, WiseTech said.

"Personal attacks on me in the media that are unconnected to the performance of the company nevertheless have the potential to encourage short-selling activity," White said in a statement.

Last month, the Sydney-based company acknowledged a report by The Australian Financial Review newspaper that White was being investigated by the federal police's human exploitation taskforce.

At the time, WiseTech said that White had assured the board that he was unaware of any such investigation, and denied any involvement in human trafficking.

"As I have stated previously, I strenuously and unequivocally deny the recent allegations in the media," White said Tuesday.

Shares in WiseTech slipped 0.9% in early trade before jumping on the announcement. They were recently up 9.4% at 38.69 Australian dollars, equivalent to US$26.92.

Murphy, the new chair, joined WiseTech in January as lead independent director. WiseTech on Tuesday said it was still looking to add another independent nonexecutive director to its board.

The company said Chief Executive Zubin Appoo had shown strong leadership in the role, but that it was focused on long-term executive succession planning.

Write to Stuart Condie at stuart.condie@wsj.com