Argentina's YPF and Italy's Eni have reached an agreement with the Abu Dhabi National Oil Company's XRG investment arm for it to join a liquefied natural gas project linked to Argentina's Vaca Muerta field, YPF said on Tuesday.

In a statement released during the Abu Dhabi International Petroleum Exhibition and Conference (ADIPEC), YPF CEO Horacio Marin said XRG's incorporation "strengthens a key initiative for the energy future of the country", and will allow Argentina to turn into a "world-class" exporter of LNG.

Eni and Argentinian state-controlled oil company YPF signed a final engineering agreement in October to export gas from the Vaca Muerta formation, the world's second-largest unconventional natural gas reserve.

YPF is leading the project, which involves installing floating liquefaction units at a port in the Patagonian province of Rio Negro. Gas will arrive from Vaca Muerta, in the province of Neuquen, via a pipeline.

Argentina, which is seeking to increase its foreign exchange reserves, could earn around $20 billion annually in exports from the project.

(Reporting by Leila Miller; Editing by Kylie Madry and Jan Harvey)