The head of a mobile phone giant says it's failed women and needs to do more to address workplace inequality.

Spark's managing director Simon Moutter said he made the realisation when a bunch of senior women left the company.

He made the admission at yesterday's Global Women Summit.

Mr Moutter told Rachel Smalley it's not just about employing women, but actually including them.

"If you don't have an inclusive environment where people feel comfortable, you can do all you like on getting the maths right, but people won't stay in those roles."

New Zealand's gender pay gap sits at 9.4 per cent.

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