On Wednesday the company said its board of directors had "unanimously rejected" the offer, saying it had failed to adequately compensate for the loss and contained too few guarantees.
"As to the decision made known publicly by the board of directors of Repsol, YPF informs that it is not true that there was an official offer from the Argentine government for the nationalisation of the business," YPF said in a statement obtained by Upstream.
"It is true that there were conversations between YPF representative and Repsol shareholders with the intention for the players to get closer to an agreement."
YPF did express approval over Repsol being "open to dialogue to reach a negotiated solution satisfatory to both companies."
Repsol saw the stake taken over last year by the government of Cristina Fernandez de Kirchner on state claims of underinvestment.
Repsol has denied those accusations and has contested the grab in international courts and tribunals, claiming it is owed in the neighbourhood of $10 billion.