A spokesperson for the publisher told DS that Creative Assembly is currently hiring for the project.
"We can confirm work is under way at Creative Assembly on an unannounced title in the Alien(s) universe and the Creative Assembly are looking for highly talented staff worldwide to help in the development process," they said.
The firm also told MCV that the game will be an "action title" and that it has an "open mind" about what platforms it will be available on.
The reveal coincides with news that the studio has expanded and is looking to increase staff members from 160 to 200 to help contribute to the project.
Creative Assembly has previously been responsible for the Total War series, including Empire: Total War and Napoleon: Total War on PC.
Sega released first-person shooter Aliens vs Predator on Xbox 360, PS3 and PC early last year.