NEW YORK — Shares in video game publisher Activision fell more than 9 per cent in premarket trading, a day after an announcement that its eight-year partnership with game developer Bungie was ending.

In the companies' joint announcement, Bungie said the separation process had already begun and that it would begin to self-publish its titles.

The companies' most successful collaboration was its Destiny series. Video game industry analyst NPD ranked Destiny 2 as the third-best selling title in 2017. NPD hasn't yet released its 2018 rankings.

The video game industry has seen an enormous shift in recent years with the massive success of games like Fortnite and PlayerUnknown's Battlegrounds, which generate revenue through players' in-game purchases as opposed to digital or physical copy sales.

The Associated Press