BP PLC (BP.L) has challenged U.S. energy regulators' approvals of a Venture Global LNG liquefied natural gas export facility, arguing the Federal Energy Regulatory Commission (FERC) has failed to enforce its regulations, according to a letter filed with FERC on Monday.

Venture Global LNG has become a major U.S. exporter of the superchilled gas since it started processing at its Calcasieu Pass, Louisiana, plant early in 2022. It has sold more than 200 cargoes of the gas under its own accounts without supplying BP and other long-term contract customers, who have complained they have lost billions in revenue.

"By failing to follow the Commission’s requirements ...(Venture Global Calcasieu Pass) has immunized its self-serving assertion that commercial operations must be deferred from the public scrutiny," BP said in its letter to FERC.

FERC oversight of LNG facility operations has not met the commissions transparency requirements, including the public disclosure of key facts and documents necessary to ensure that commission’s rulings are in fact being followed, BP wrote.

A FERC spokesperson declined to comment, citing pending matters before the commission.

BP's action follows the denial of a request by Spanish energy firm Repsol SA (REP.MC) for the reopening of U.S. authorization of facility. It asked the Department of Energy to revisit the export approval of the 10 million metric tons per year Calcasieu plant in view of startup problems that has prevented Repsol from receiving its contracted LNG cargoes.

"The complaint that BP filed with FERC has no merit and is another attempt, after Repsol tried and failed, to use a federal energy regulator to advance its own interests in a commercial dispute,” Venture Global LNG spokesperson Shaylyn Hynes said.

Venture Global LNG will be submitting a formal response to the BP letter, she added.

In the Repsol request, the DOE denied the request to open the approval, and said disagreements with contract terms and performance were a matter for the commercial parties to resolve.

"DOE has no basis to second-guess FERC’s determinations concerning the operational status of the Project," the DOE's November decision said.

The latest request comes after BP, Edison SpA, Shell and Repsol filed contract arbitration claims on the lack of LNG cargoes under their contracts.

Venture Global LNG has said the claims are without merit and the company's contracts allow it alone to decide when the facility is operating commercially.