Valve president and cofounder Gabe Newell tells Games for Change Festival audience that the recently released platformer has already gone triple platinum.

Earlier this week, the
Games for Change Festival kicked off with
a keynote address from former Vice President Al Gore. Today, the New York-based event was the scene of a speech from another executive–Gabe Newell, president and cofounder of Valve Corporation.

According to gaming blog Joystiq, Newell used his speech to announce a major sales milestone for the critical darling Portal 2. Since its launch on April 19, the game has “sold” 3 million units, Newell reportedly said. He did not specify whether that figure referred to sold-in (that is, shipped) copies or represented games sold through to consumers.

Newell didn’t say whether the figure included sales on Steam, Valve’s online distribution platform for the PC and Mac. He also declined to clarify whether that figure included cumulative sales on all the platforms Portal 2 was released on–the PC, Mac, Xbox 360, and PlayStation 3.

As of press time, Valve reps had offered no official confirmation of Newell’s comments.

Portal 2 has reached its sales milestone far faster than its predecessor, Portal. On the day its sequel launched,
Valve confirmed to GameSpot that the original game had sold over 4 million units since its launch in October 2007. That figure did not include Steam sales of Portal, but it did include sales of the compilation The Orange Box, which included Portal, Team Fortress 2, Half-Life 2, and the latter shooter’s first two expansions.