Dairy company Fonterra has back-flipped on the look of a planned event for International Women's Day after the gender lineup left a sour taste. 

New Zealand's biggest business was howled down on social media when it promoted a planned panel discussion themed "Breaking the Bias" with an all-male staff lineup. 

Responding to Twitter critics, the company said the panellists were "male allies", who would be talking about the important role males play in helping to overcome bias in the workplace. 

In a statement since, the company said it had changed the composition of the panel. 

"We recognise that we did not get this event right. We have reviewed the panel and changed it to two women and one man," said Kate Daly, Fonterra managing director people & culture. 

"It's important that we have both men and women talking about gender diversity so that we can all work together to overcome gender bias in the workplace. 

"This is one of many events we have lined up for International Women's Day. We are committed as a business to improving gender diversity and breaking down barriers that exist for women." 

Fonterra, which reported last year that 32.4 per cent of its senior leadership were females, said in its Twitter response on Thursday: "We know this doesn't look great and want to share a bit more context. We have a range of events lined up for International Women's Day. We have inspiring females sharing their stories and this panel of male allies talking about the important role males play in helping to overcome bias in the workplace. Both views are equally as important to achieve change. We're really committed to improving gender diversity." 

International Women's Day is on March 8.