(Adds Williams comment, Sierra Club not immediately available for comment)
Nov 8 (Reuters) - A U.S. federal appeals court on Wednesday lifted a temporary stay of construction on Williams Cos Inc's nearly $3 billion Atlantic Sunrise natural gas pipeline from Pennsylvania to South Carolina.
Some energy traders had worried the stay could have caused a delay in the pipeline's in service date, which would keep gas trapped in the Marcellus shale.
Williams has said it expects to complete the pipeline in mid-2018. Atlantic Sunrise will transport up to 1.7 billion cubic feet of gas from the Marcellus shale in Pennsylvania to markets in the U.S. Mid Atlantic and Southeast.
One bcfd is enough gas for about 5 million U.S. homes.
The U.S. Court of Appeals for the District of Columbia dissolved the Nov. 6 stay on Wednesday because the petitioners opposed to the pipeline "have not satisfied the stringent requirements for a stay pending court review."
We will promptly resume construction activities on this important pipeline project, which will leverage existing energy infrastructure to deliver economic growth and help millions of Americans gain access to affordable Pennsylvania-produced clean-burning natural gas," Chris Stockton, a spokesman at Williams said in an email.
The Sierra Club and other opponents of the pipeline secured the stay with a filing last week.
Officials at the Sierra Club were not immediately available for comment.
On Tuesday, Williams said the purpose of the stay was to give the court sufficient opportunity to consider the emergency motion and should not be construed in any way as a ruling on the merits of the pipeline opponent's motion.
Atlantic Sunrise has undergone a nearly four-year, extensive review process and is operating and being constructed in compliance with all state and federal permits, said Micheal Dunn, Williams Partners chief operating officer.
Analysts at Simmons & Co, energy specialists at U.S. investment bank Piper Jaffray, said in a report earlier on Wednesday that they did not anticipate a prolonged stay, according to a report about Cabot Oil & Gas Corp, which expects to use Atlantic Sunrise to transport gas.
Cabot has secured about 1 bcfd of transport capacity on Atlantic Sunrise. Simmons said they do not expect Cabot to ramp up production into Atlantic Sunrise until the fourth quarter of 2018.
The temporary stay was a result of a lawsuit against the U.S. Federal Energy Regulatory Commission for not extending the permitting process, Williams said.
Williams warned the stay put 8,000 jobs at risk in Pennsylvania.
(Reporting by Scott DiSavino; Editing by Andrea Ricci)