HOUSTON May 14 - Williams Cos on Tuesday said it was confident a natural gas pipeline project underway in Texas and Louisiana had not violated federal regulations, after rival Energy Transfer filed a report pushing for further regulatory review.

The two companies have been in dispute over Williams' Louisiana Energy Gateway (LEG) Project, under construction in Texas and Louisiana, after Energy Transfer pushed back on the line for crossing its own systems.

The 1.8 billion-cubic-feet-per-day (bcfd) system was supposed to begin service this year, but has been delayed until the second half of 2025 following the dispute.

"Ultimately I think Energy Transfer sees the writing on the wall, that their legal cases in court aren't going to work for them, so they chose to go to the FERC," Micheal Dunn, executive vice president and chief operating officer at Williams told Reuters on Tuesday.

Energy Transfer last month requested the Federal Energy Regulatory Commission (FERC) consider whether it should regulate the pipeline and re-examine gathering policies. The FERC does not regulate gathering pipelines, but it does oversee transmission pipelines that cross state lines.

The two companies have disputed whether the line should be regulated by the federal agency.

"We are confident the FERC will conclude that the LEG is a gathering pipeline system. This is clearly anticompetitive behavior on their (Energy Transfer's) part," Dunn said.

The line would feed gas from the Haynesville shale field to the U.S. Gulf coast.

"We are going to build our pipeline project, we have committed to our shippers and the production needs to move out of the area," Dunn said.

Energy Transfer did not respond for comment. (Reporting by Georgina McCartney in Houston; Editing by Liz Hampton and Marguerita Choy)