Shares of Argentina's leading energy company YPF slumped 23 percent on Wednesday after officials said the government would not pay majority holder Repsol what it wants for control of the firm.
Argentina on Monday unveiled its plan to nationalize YPF , in which Spain's Repsol has a 57 percent stake.
YPF shares had taken a beating in the run-up to the announcement. On Wednesday they sold off again, to 82.7 pesos per share from Tuesday's (1715 GMT) close of 108 pesos in Buenos Aires, as investors figured in the cost of the expected looming spat over the price that Argentina is willing to pay for 51 percent of the company.
Late on Tuesday, Argentina said it did not intend to pay the $9.3 billion that Repsol is demanding for 51 percent of YPF.
"Everyone knew the risk of nationalization was high," said one local economist who is following the YPF saga. "But now there's more information out there about the price that Argentina is willing to pay for a controlling stake in YPF."
The company's U.S.-listed shares were down 27 percent in afternoon trade in New York.