LONDON—Argentina is about to export its first LNG cargo from a new floating facility, marking a milestone for its energy sector boosted by rising gas production from its large Vaca Muerta shale region.

State energy firm YPF is believed to be offering a partial LNG cargo from FLNG Tango, the liquefaction vessel off Bahia Blanco, two LNG trading sources said on May 20. One source said the cargo was on a free-on-board (FOB) basis for prompt loading.

FLNG Tango, owned by Belgian shipping company Exmar, arrived in Bahia Blanca in February.

Argentina will become the 21st country to export LNG. It has long bought LNG, alongside buying pipeline gas from neighboring countries and producing its own, to boost supplies, especially during winter.

But rising output from Vaca Muerta, one of the world’s largest reserves of shale oil and gas, helped it reduce LNG imports by over 20% last year to 2.6 million tonnes, according to industry group GIIGNL.

The new exports do not mean Argentina will cease importing LNG; energy firm Integracion Energetica Argentina (IEASA), formerly known as ENARSA, has issued buy tenders for LNG cargoes for delivery throughout May to September.

The country needs billions of dollars in investment into the construction of pipelines, storage terminals and other energy infrastructure to fully benefit from its shale resources.

In many countries with a fast-developing energy industry, bottlenecks and price moves can mean that some regions are left energy poor while others export. Major LNG exporter Australia, for example, is seeking to import LNG soon.