ANCHORAGE, Alaska – Alaska Gov. Sarah Palin has signed a bill authorizing the state to award a license to TransCanada Corp. to start developing a natural gas pipeline.

Palin signed the bill on Wednesday in Anchorage, and expects the license to be issued within three months. The license allows TransCanada to move forward on plans to develop the 1,715-mile pipeline from a treatment plant at Prudhoe Bay to the Alberta hub.

The license ends a decades-long battle to open up North Slope natural gas for use in North American markets, with 4.5 billion cubic feet of natural gas to be shipped daily.

The license does not guarantee construction, but it means TransCanada can move forward on costly federal permitting applications. The project is estimated to cost between $26 billion and $30 billion.

The state says TransCanada has already authorized specific aerial photography, engineering work and environmental gap analysis.