HOUSTON (Reuters) - U.S. liquefied natural gas developers awaiting permits for new export projects this week expressed confidence President-elect Donald Trump will ease the way for their multi-billion-dollar expansion plans.

Their confidence is buoyed by Trump's promise to end an expanded Department of Energy review that has slowed new export permits. President Joe Biden had paused new non-FTA export permits and asked the DOE to more broadly evaluate the cumulative effects of new LNG projects' climate and economic impacts.

Environmental groups pledged to keep up the pressure to block new plants.

Trump's victory will ensure the nation will have "some rational, reasonable people running this country," said Marshall McCrea, co-CEO of LNG and pipeline operator Energy Transfer. The change of administration assures a financial go-ahead for its $13-billion LNG-export facility in Louisiana, he said on a quarterly call.

Commonwealth LNG, which is developing a $10-billion facility near Cameron, Louisiana, and has been waiting for an LNG-export permit for more than 18 months, said it is looking forward to approval of its non-FTA authorization. That term refers to exports to non-Free Trade Agreement countries that account for the vast majority of U.S. LNG purchases.

Sempra LNG, which plans to build a second phase of its Texas-based Port Arthur LNG, now expects the Trump victory will lead to an export permit by June.

"We have growing confidence in getting the permits we need for Port Arthur Phase 2 in the first half of next year," Sempra CEO Jeffrey Martin said on Wednesday on a quarterly call. The project would add two liquefaction processing units to the two under construction.

Environmental groups that helped convince the Biden administration to reconsider the wider impact of LNG exports, say they will continue to challenge the permits.

"We will do everything we can to fight back against attempts to trample on safeguards meant to protect people from polluted water and air," said Mahyar Sorour, director of the Sierra Club's beyond fossil fuels policy.

Venture Global LNG, which has not received a non-FTA export permit for its 20-million-metric-ton-per-annum Calcasieu Pass 2 plant in Louisiana, said it looks forward to working with the incoming administration.

The expected loosening of some LNG regulations means a clear runway for developers, said Fred Hutchison, CEO of trade group LNG Allies.