The name change had been expected following the discovery of a new domain name last month, however, nothing had been confirmed until now.
According to Eurogamer, THQ made the announcement during yesterday's end-of-year financial earnings call, and revealed that the game will have a bigger budget than its predecessor.
The game will also be one of a number of THQ titles in development to offer 3D visuals, as well as De Blob 2 and Saint's Row on the 3DS.
Metro 2033 was released on Xbox 360 and PC in March last year. The game was developed by 4A Games and takes place in the underground system of a post-apocalyptic Moscow.
> The Gaming Post-apocalypse
Watch the trailer for Metro 2033 below: