The US Supreme Court cleared the way for Equitrans Midstream Corp. to resume construction on its controversial Mountain Valley Pipeline, lifting lower-court orders that had blocked work on the $6.6 billion project.

The court’s order Thursday allows work on the project to resume, but for now lets the pipeline’s environmental opponents press ahead with their case. The Supreme Court gave no explanation and no justice publicly dissented.

The high court stopped short of tossing out the environmental groups’ lawsuits altogether, something the pipeline had suggested as an alternative. But the justices left open the possibility they might do so at a later stage, saying, “that determination is without prejudice to further consideration in light of subsequent developments.”

The Supreme Court issued the order even as the 4th US Circuit Court of Appeals heard arguments in Richmond, Virginia, about next steps in the case.

Shares of Equitrans jumped 9.5% as of 11:01 a.m. in New York trading.

The roughly 300-mile (483-kilometer) pipeline, backed by Democratic Senator Joe Manchin, cuts through the Appalachian Mountains, a national forest and hundreds of stream crossings as it carries natural gas from his home state of West Virginia to southern Virginia, and has drawn fierce opposition from environmental activists.

Read More: Court Stalls Pipeline That Joe Manchin Thought It Couldn’t Touch

Equitrans has said it has three months of work remaining to complete the project and needed to resume construction by Wednesday in order to put the pipeline into service before year-end.

The 4th Circuit temporarily blocked construction earlier this month despite language in recently enacted debt-ceiling legislation that was intended to prevent the pipeline from being stalled by the lower court, which has repeatedly ruled against the project.

(Updates with further details starting in third paragraph.)