Valve has filed for a trademark on Half-Life 3 in Europe, and while the company is yet to comment, it could suggest a third instalment of the infamous first-person shooter series is on its way.
According to NeoGAF, the trademark application was filed on 29 September with the European Union's Office of Harmonization for the Internal Market (OHIM).
Valve CEO Gabe Newell has previously said that the studio had gone through numerous 'twists and turns' to bring Half-Life 3 to market and explained that Valve's silence was in the best interest of gamers because elaborating on the game's development "would probably drive people more crazy."
A Valve representative is still to confirm a potential sequel but Polygon reports that the HL3 trademark is reserved for Europe and not currently registered in the United States.
Half-Life 2 was released in November 2004 after a protracted development cycle. The most recent entry in the series, Half-Life 2: Episode Two, was released Oct. 10, 2007.
Valve is currently working with Star Trek director JJ Abrams on a game-film adaptation of the hit franchise. A trademark in essence means nothing - but it could mean everything.