Parnell said he received a letter from the BP, ConocoPhillips, Exxon Mobil and TransCanada on what the governor said would be one of the largest LNG projects in the world.
"This represents historic progress," Parnell said. "Never before has a gasline project been so specifically aligned and described in detail by the companies that have the capacity to build, fill and operate it."
The companies before summer are expected to finalize an agreement on preliminary design and engineering work on the project.
The underground pipeline would run from the North Slope of Alaska and would carry around 3 billion cubic feet of natural gas per day to facilities that would process LNG.
The companies estimate the project represents an investment of $45 billion-$65 billion.
Parnell's administration has pushed to get more of Alaskan natural resources available for export markets.