Spain is open to negotiating a new bailout for Greece, which should remain in the eurozone, Economy Minister Luis de Guindos said Monday after Greek voters rejected creditors' austerity demands in a weekend referendum.

Athens "has the right to ask for a third rescue package. The Spanish government is open to these negotiations," he told a news conference.

"Given the circumstances, from the point of view of the markets it is absolutely necessary," he added.

Spain is "absolutely not contemplating a Greek exit from the euro", the minister said in the first reaction from Spain's conservative government to the outcome of the Greek referendum.

Despite warnings from European leaders that Sunday's referendum was effectively an in-out poll on the euro, more than 60 percent of the Greek voters heeded their government's call to vote "No".

Greek Prime Minister Alexis Tsipras had argued during the campaign that a "No" vote against accepting debt reform proposals from Greece's creditors -- the so-called "troika" made up of the European Central Bank, the European Commission and the International Monetary Fund (IMF) -- would strengthen his hand in future negotiations.

De Guindos recognised that Greece's creditors had made "mistakes" in their handling of the crisis.

"I think that there were mistakes on the part of the troika, but it is inevitable that Greece make reforms because there have been nations that have done them and they are emerging from the crisis," he said.

Spain was battered by the global financial crisis and only emerged from a double-dip recession at the end of 2013.

Its economy has grown for the past seven quarters although the jobless rate remains high at 23.8 percent, the highest in the European Union after that of Greece.