CHARLESTON, W.Va. — A panel of federal appeals judges has vacated a key permit for the Atlantic Coast Pipeline, which would stretch 600 miles, beginning in Harrison County and four more West Virginia counties before extending through Virginia and into southeastern North Carolina.

A three-judge panel from the Fourth Circuit Court of Appeals in Richmond on Tuesday announced a ruling that would invalidate a key U.S. Fish and Wildlife Service review.

The appeal was part of a series of efforts by environmental groups to halt construction of the natural gas pipeline.

Dominion Energy, which is the parent company of the pipeline project, contends the ruling covers only parts of the project and that construction may continue along much of the route.

The environmental groups challenged the U.S. Fish and Wildlife Service’s Incidental Take Statement, which is meant to set limits on killing threatened or endangered species during construction and operation.

The environmental groups argued that the limits under the policy are not clear.

The appeals judges — Chief Judge Roger L. Gregory and Judges Stephanie D. Thacker and James A. Wynn Jr. — agreed.

“We conclude, for reasons to be more fully explained in a forthcoming opinion, that the limits set by the agency are so indeterminate that they undermine the Incidental Take Statement’s enforcement and monitoring function under the Endangered Species Act,” the judges wrote.

“Accordingly, we VACATE the Fish and Wildlife Service’s Incidental Take Statement.”

The Sierra Club celebrated the ruling as a victory that would stop pipeline construction.

“The permit is required to construct the fracked gas pipeline, and with it being vacated, the project must be halted,” stated Jonathon Berman, a spokesman for the Sierra Club.

Construction of the pipeline will continue while Dominion reviews the court’s decision, stated company spokeswoman Jen Kostyniuk.

“This decision only impacts activities directly covered by the Incidental Take Statement in certain defined areas along the route,” Kostyniuk said in a written statement.

“We will fully comply as required while we continue to construct the project. Although we disagree with the outcome of the court’s decision, and are evaluating our options, we are committed to working with the agency to address the concerns raised by the court’s order.

The $5.1 billion pipeline project has had to work its way through state and federal regulatory requirements. Several have been challenged along the way by environmental groups.