Axel Kicillof headed by Hernán Lorenzino. After that, on November 18, 2013, Kicillof officially became Minister of Economy. Kicillof was instrumental in the renationalization of YPF. President Cristina Fernández de Kirchner named Kicillof to the post of Secretary (or Deputy Minister) for Economic Policy and Development Planning in December 2011. He took academic leave to assume this post. In this position, Kicillof oversaw the controversial 2012 nationalization of YPF, the Argentine oil company then controlled by the Spanish energy firm Repsol. It was the largest expropriation in Argentina's history. He justified this action as part of a needed reversal of the Argentinian
Repsol of the massive Vaca Muerta shale-gas field. The board of the Repsol firm unanimously rejected this offer, as it would have caused them to drop a $10.5 billion lawsuit that was in progress against the Argentine government. Repsol at the time owned 6.4% of the YPF oil-and-gas company. On 25 February 2014 the Repsol board announced it had accepted a settlement offer from the Argentine government of an issue of Argentine bonds valued at $5 billion. The deal concluded after 3 months of negotiations in Buenos Aires was subject to shareholder approval. The agreement ended two years of legal wrangling