HOUSTON, Aug 6 (Reuters) - Sempra Infrastructure's

Energia Costa Azul LNG export project in Mexico has been further

delayed by labor and productivity challenges that will boost the

project's cost, the company said on Tuesday.

Sempra Infrastructure, a unit of utility giant Sempra ( SRE )

, has been building the first phase, a 3.5

million-metric-ton per annum (MTPA) liquefied natural gas train

for the LNG export project in Mexico. The facility will give the

company direct access from Mexico's Pacific coast to feed LNG

markets in Asia.

"We are actively engaged with our contractor to advance the

project, and we'll see increased features for the projects in

the form of additional carrying costs," Sempra ( SRE ) Chief Financial

Officer Karen Sedgwick said on an earnings call.

She did not give a new cost estimate. In 2020 the company

said it planned to spend about $2 billion for the first phase.

Sedgwick said the higher construction costs are unlikely to

hurt the project's economics because there will be lower

estimated commissioning rent based on forward price curves.

"Despite the delay (and the) potential changes in capital,

we still expect to maintain strong integrated financial returns

with our original forecast at the time that we took FID (the

final investment decision) in 2020," Sedgwick said on the

earnings call.

She cited factors including optimization opportunities,

stronger LNG demand over the long term and inflation protection

within the sales and purchase agreement.

The First LNG from the export project is set for 2025, with

contracted customers receiving supplies in spring 2026, Sempra ( SRE )

said in its second-quarter earnings report.

Of the 3.5 MTPA in phase 1 of the project, 2.4 MTPA of that

capacity has been contracted to France's TotalEnergies

and Japanese trading house Mitsui & Co ( MITSF ), according to

the company's website.

Sempra ( SRE ) also said it hoped to create efficiencies by moving

seamlessly between the two phases of its Port Arthur, Texas, LNG

projects by using the same contractor, Bechtel.

"We're excited as the project moves forward while

targeting cost to construction efficiencies by having them roll

uninterrupted from phase one to phase 2," said Justin Bird,

Sempra's ( SRE ) executive vice president.

U.S. LNG projects have recently faced

cost escalation

due to shortages of skilled labor.

Phase 2 would add an additional 13 MTPA to phase 1's 13

MTPA currently under construction. Phase 1 is expected to cost

$13 billion. Sempra ( SRE ) recently signed a fixed-priced contract with

Bechtel for an undisclosed sum to construct phase 2.