Job ad suggests that a next-gen Halo could already be in production at Halo 4 dev.
343 Industries is staffing up for a next-generation Halo title, according to a job listing uncovered by VideoGamer.
The job ad, which was posted on Microsoft's careers website yesterday, states that "343 Industries is looking for an experienced graphics developer to help create the current and next generation of game visuals in the Halo universe."
"Work on one of the most exciting and creative properties in the industry," the ad states.
"Work with the incredible 343 team to help drive the future of Halo.
"We are looking for an experienced graphics developer to help us deliver cutting edge graphics technologies for AAA experiences. Candidates should understand and have experience with how to bring great graphics to life."
Later, the job ad says that "DX11 experience is a plus".
DirectX 11 is heavily-rumoured to be the graphical framework around which the next-generation Xbox is based.
343 Industries is currently developing this year's Halo 4 - a title which has previously been rumoured to be in development for a next-generation Xbox.
Other job listings posted earlier this month also point to a new Halo game in production at 343 Industries.
A job ad posted on July 5 asks for an environment artist "to help breathe a fresh vision into a new Halo experience", while a second, posted on July 11, asks for a creative director to "lead and deliver a groundbreaking new AAA entertainment experience set in the Halo universe."
Another asks for a designer to help "spearhead efforts to design the next wave of Halo experiences".
343 is the second Microsoft-owned studio whose job ads have pointed at next-gen development.
Back in May, job ads for Rare suggested that the developer was developing "new IPs for future platforms".
Microsoft has yet to announce plans for its next-generation console.