ConocoPhillips is preparing its 50-year-old Kenai liquefied natural gas export facility in Alaska for long-term shutdown as LNG exports from the lower 48 states grow.

The US independent plans to scale back operations at the plant this fall, ConocoPhillips Alaska spokeswoman Amy Burnett wrote in an email.

"The reduced operations will focus on continued preservation of the facilities for future LNG exports," Burnett said.

"The timing is right to begin planning to transition the Kenai LNG plant for a long-term shutdown. The period for the plant being in this mode will be dependent on market conditions."

In 2015, Kenai LNG operated for six months and liquefied 20 billion cubic feet of gas.

Due to market conditions, an export programme did not occur in 2016.

Meanwhile, the US is on track to become one of the top three natural gas exporters in the coming years as a number of facilities in the lower 48 (primarily on the US Gulf Coast) come online.

ConocoPhillips hopes to sell the plant in order to focus on its North Slope operations, such as the Greater Moose's Tooth unit where it announced a potential 300 million barrel discovery earlier this year.

The facility has been on the market since mid-January but does not have a buyer yet. Burnett said conversations with interested parties are ongoing.