Borderlands 2 has become 2K's highest-selling game of all time with more than 8.5 million units shipped to date, Take-Two Interactive announced during its third-quarter financials last night.

"Borderlands 2 is a prime example of how we are able to generate substantial revenue and profits from add-on content over an extended period," explained Strauss Zelnick, chairman and chief executive officer during the publisher's earnings call.

"In the 16 months following the title launch, we released nine substantial downloadable offerings, dozens of smaller character customizations, and we have plans to release more downloadable content in the coming months. This is an addition of package good, add-on packs, and most recently, a Game of the Year Edition."

He added: "The popularity of add-on content for Borderlands 2 is an important contributor to the title's becoming the highest selling release in history of 2K with more than 8.5 million units sold-in to date."

Neither 2K or developer Gearbox have yet confirmed that Borderlands 3 is in development.

Given the huge player base involved in Borderlands 2, a third title must be in the publisher's plans for the Xbox One and PS4.

Source: Press release, Seeking Alpha