A proposal for a high-voltage power line carrying wind energy across the Midwest received a jolt of new life Tuesday as the Missouri Supreme Court ruled that state regulators had wrongly rejected it.

The ruling is a major victory in the quest by Clean Line Energy Partners to build one of the nation's longest electric transmission lines. The $2.3 billion project would carry power harnessed from the wind-whipped plains of western Kansas on a 780-mile (1,255 kilometer) trek across Missouri and Illinois before hooking into an electric grid in Indiana that serves the eastern U.S.

"The project has been on standby while we awaited the Missouri Supreme Court decision," Clean Line President Michael Skelly said. "Now with this decision, we can get back after it."

Missouri had been the lone state blocking the project. But during Missouri's protracted regulatory and legal battle, an Illinois appeals court in March also overturned that state's approval.

Skelly said the Houston-based renewable energy firm still has a clear path toward winning Illinois approval by first acquiring ownership of some utility property and then reapplying.

Attorney Paul Agathan, who represents more than 1,000 members of the Missouri Landowners Alliance, said his clients would continue fighting the power line before state regulators and county commissioners, who still would eventually have to sign off on permits for the power line to cross roads.