(Reuters) -Venture Global ( VG ) shares slumped 17% in premarket trading on Friday after BP won its arbitration case against the U.S. supplier over its failure to deliver liquefied natural gas under a long-term supply deal that was due to start in late 2022.

The International Chamber of Commerce International Court of Arbitration found that it had breached its obligations to declare commercial operations had begun at the Calcasieu Pass plant in a timely manner and act as a "reasonable and prudent operator," Venture Global ( VG ) said on Thursday.

BP, Shell, Edison and Galp had filed arbitration claims accusing the U.S. company of profiteering by selling LNG commissioning cargoes at higher spot market prices, rather than at long-term contracted prices.

The ruling marks a setback for Venture Global ( VG ), which had previously prevailed in the arbitration brought by Shell.

RBC Capital Markets analyst Elvira Scotto said the unfavorable result in the BP case was "somewhat of a surprise" and could rekindle investor concerns associated with the pending arbitration proceedings.

BP is seeking to recover damages of more than $1 billion plus interest, costs and attorneys' fees, which will be determined at a separate hearing expected in 2026.

Venture Global's ( VG ) shares have dropped about 48% since its January 24 debut, giving it a market capitalization of roughly $30.5 billion as of last close.

(Reporting by Vallari Srivastava in Bengaluru; Editing by Sriraj Kalluvila)