The a2 Milk Company Chief executive officer Jayne Hrdlicka has resigned from her position after one year in the role.
Ms Hrdlicka said the future growth of the company would be "too difficult to manage" despite the company being an "extraordinary business".
“The reality, however, is that the next three to five years will continue to require the chief executive officer being present in our core markets of China and the US and that, combined with running a New Zealand company based in Australia, required more travel than I had anticipated when I joined the company,” she said.
Also the chair of Tennis Australia, Ms Hrdlicka decided the position would be too much to juggle alongside other commitments and her general health.
Former chief executive officer Geoffrey Babidge has accepted the role as interim chief executive officer effective immediately.
“The board wishes to thank Jayne for the important contribution she has made to the company and remains confident that the strategic course of the business, which was recently communicated at the annual meeting, will continue to deliver strong rewards to all shareholders in the future,” Mr Babidge said.
Ms Hrdlicka said she would work with chairman David Hearn and the new chief executive officer to ensure a smooth transition.
Mr Hearn said the board had begun a global search for the new chief executive officer.
“The board will work closely with Geoff Babidge to prosecute the current strategy whilst searching for the right full-time candidate to take the company forward,” Mr Hearn said.