Sept 18 (Reuters) - New York's utility regulator told

some U.S. units of UK energy firm National Grid on

Thursday to report on how they will optimize natural gas supply

sources if the proposed Northeast Supply Enhancement or NESE

pipeline project is or is not placed into service.

If NESE, proposed by U.S. energy company Williams Cos

Transco unit to increase gas supplies from Pennsylvania

into New Jersey and New York, is not placed into service, the

New York Public Service Commission (NYPSC) said it wanted the

National Grid companies to report on how they will address

reliability concerns.

The three National Grid utilities - Brooklyn Union Gas,

KeySpan Gas East and Niagara Mohawk Power ( NMPWP ) - serve about 2.5

million gas customers in New York, making them the state's

largest natural gas delivery system, the NYPSC said.

Williams canceled its first attempt to build NESE in 2024

largely due to opposition from New York and New Jersey

environmental regulators. It revisited the project earlier this

year with support from U.S. President Donald Trump's

administration.

NESE and another proposed gas pipe proposed by Williams, the

Constitution Pipeline from New York to Pennsylvania, have been

linked to a deal between the Trump administration and New York

Governor Kathy Hochul to lift a federal stop-work order on

construction of Norwegian energy company Equinor's ( EQNR )

Empire Wind offshore wind project off New York.

While Hochul did not specifically endorse any gas pipes, she

did say New York would work with the U.S. administration and

private entities on projects that meet legal requirements under

state law.