By Maximilian Heath

BUENOS AIRES, April 9 (Reuters) - Argentine state energy firm YPF has cut production by around half at its giant Vaca Muerta shale development Loma Campana due to a slump in demand amid the global coronavirus pandemic and a nationwide lockdown, local media reported on Thursday.

Loma Campana is the most important development site for YPF in Vaca Muerta, a formation in Patagonia similar in size to the whole of Belgium and thought to be home to one of the largest unconventional reserves in the world.

Regional newspaper Diario Río Negro said YPF had cut production by around 50% at the flagship prospect, hit by a national quarantine that has been in place since mid-March and has sapped domestic demand.

YPF declined to comment on Thursday.

Global shale firms have been hurt badly by the global pandemic as well as an oil war that has dashed prices. OPEC and its allies agreed on Thursday to cut their oil output by more than a fifth to prop up prices.

YPF, which is developing the Loma Campana concession with Chevron Corp, describes it as the top non-conventional development outside North America.

Argentina has recorded close to 2,000 confirmed cases of coronavirus with around 70 deaths. (Reporting by Maximilian Heath; Writing Adam Jourdan)