Malaysian oil giant Petronas on Tuesday signed a preliminary agreement with Argentinian firm YPF to invest in the giant gas and shale oil field at Vaca Muerta, a statement said.
Petronas has expressed interest in a shale oil field in Neuquen province at the foot of the Andes in western Argentina, said a statement from YPF, which was nationalized in 2012 at the expense of Repsol.
Argentina has launched a global drive for foreign investment in Vaca Muerta, seen as one of the most potentially lucrative fields in the world.
German firm Wintershall, US giant Chevron and Chinese-Argentinian company Bridas have already announced more than $5 billion worth of investment seeking to exploit unconventional hydrocarbons at Vaca Muerta.
French company Total is conducting exploration at the site while Russia's Gazprom and Mexico's Pemex have also been approached.
Argentina reported an energy deficit in 2013 of $8 billion and is keen to boost domestic production to limit imports.