A spokeswoman told the Mirror: “ Under Armour is ending its relationship with Sarah Bowmar, the wife of Josh Bowmar.
“The method used to harvest this animal was reckless and we do not condone it.
“Under Armour is dedicated to the hunting community and supports hunting that is conducted in compliance with applicable federal, state and local laws and hunting practices that ensure a responsible and safe harvest of the animal.”
Previously the company stressed Bowmar’s bodybuilding husband was not “an Under Armour-sponsored athlete”.
Bowmar later confirmed the news in a tweet, saying: "Under armour and the Bowmars broke up today. I'll do a blog post in a few days when I am no longer crying. #AntisWon."
In January, the Baltimore-based firm, which supplies Tottenham Hotspur, announced their first ever hunting campaign featuring for women.
“The UA women’s hunt campaign aims to educate, engage and empower female hunters, while celebrating the physical and inner fortitude of those women that bravely pursue their own path,” they said.
“The campaign will feature top-notch female authorities in the outdoor industry.
Calling them a “Women of Will arsenal” they described Sarah Bowmar as a” revered fitness guru and bowhunter.”
On the video of the bear being speared both Bowmar’s wear Under Armour clothing. The killer is dressed head-to-toe in their apparel while Sarah sponsored gloves are seen as she films the attack.
At one point she fist bumps her husband in celebration.
Animal campaigners said it could have taken up to 20 hours for the animal to die.
Since the Mirror revealed the bear's sick death Canadian authorities have said they will bring a ban in on spear hunting while also investigate Josh Bowmar for any criminal charges.
The couple has previously conducted a tour of the US filming it for their YouTube channel.
Their vehicle is covered in Under Armour livery while they title the video of the tour “Cabelas and Under Armour Forest Truck Tour”.
Cabelas is a chain of outdoor stores with a heavy focus on hunting.
Under Armour sponsors some of the world's leading athletes including Andy Murray, Michael Phelps and Jordan Speith.