By Alexandra Alper
SANTA CRUZ, Bolivia (Reuters) - Representatives from a group of major energy-exporting nations on Friday said they oppose the use of unilateral sanctions on any of their members - an apparent dig at the United States for its moves against Russia, Iran and Venezuela.
The Gas Exporting Countries Forum, which also includes members like Libya, Equatorial Guinea and Nigeria, expressed their "profound concern" about sanctions affecting the gas sector that are not authorized by the United Nations, according to a communique signed by GECF's 12 members after the group's summit in Bolivia this week.
The U.S. Congress has imposed economic sanctions on a number of GECF's members, including recent measures against Russia that - among other things - seek to prevent companies from participating in Russian pipeline projects.
Russia is the world's second biggest natural gas producer behind the United States, which is not a GECF member, and depends heavily on its pipeline systems to reach its main customers in Europe.
Russian Energy Minister Alexander Novak said earlier on Friday that the United States should not be permitted to impose such sanctions without a vote of the United Nations Security Council, of which Russia is a member.
Washington also has imposed sanctions this year on Venezuela to pressure President Nicolas Maduro's regime and has threatened to reimpose some sanctions against Iran that were lifted as part of a 2015 deal to freeze its nuclear programme, brokered by former President Barack Obama.
President Donald Trump has said Iran is violating the "spirit" of the 2015 deal.
While Iran and Venezuela produce some gas and are vocal members of the GECF, neither exports gas.
The GECF communique on Friday said its membership would agree to cooperate towards a sustainable global natural gas market, while promoting the fuel's use.
The meeting came as GECF members struggle with slumping global gas prices, blamed largely on surging supply from the United States and elsewhere, that have reduced investment and returns in parts of the industry.
Novak said the oversupply on the world market could trigger a "crisis" drop in prices, similar to what occurred in the crude oil market.
Gas prices already have plunged more than 80 percent in the past decade and remain under pressure due to growing supplies of shale gas and increased availability of liquefied natural gas (LNG) that can be shipped overseas.
The United States has been able to vastly increase its output of oil and gas in recent years as improved drilling technology opened previously inaccessible reserves (CLc1) (NGc1).
The GECF is modelled after the Organization of the Petroleum Exporting Countries (OPEC), whose 12 member nations manage oil supply to control prices. While the GECF has called for increased cooperation to defend its gas market, it has not applied production limits as OPEC has done.