General manager Arthur McBride said the avalanche occurred on Pito Peak in the vicinity of the Arrowsmith Range during a guided day with Methven Heliski about noon.
The guide leading the group was buried by the avalanche and was extracted, but did not survive.
The other skiers were not hurt.
McBride said the guide was a "much-loved friend and colleague", and their thoughts were with his family and friends at this time.
WorkSafe is investigating.
There have been several deaths of heli-skiing guides and skiers over the years.
In August 2015, Roger Greville died after being buried by an avalanche near the Devil's Staircase, in the Kingston area. The 58-year-old Australian man had been on a trip with Southern Lakes Heliski.
In 2009, an Australian skier and a guide working for Alpine Guides were killed in two separate avalanches in the Ragged Range, inland from Ashburton.
Llynden Riethmuller, 61, died in an avalanche while heli-skiing with a group on 24 July.
One of the guides on that trip, Jonathan Morgan died after being caught in an avalanche in the same area during another heli-skiing trip, three weeks later.
The company said at the time that the two deaths within a month were the first avalanche fatalities the company had in 21 years.
