By Daniel Flynn

RIO DE JANEIRO (Reuters) - Olympics organizers said on Sunday they will appeal a judge's decision blocking them from using public money amid a deep recession in Brazil but insisted they would have enough funds to successfully stage the Games and next month's Paralympics.

Judge Marcia Maria Nunes ruled late on Friday that the federal government and the city of Rio de Janeiro could not provide some 270 million reais ($85 million) promised to help pay for the opening and closing ceremonies of the Games and next month's Paralympics.

"We can guarantee that we are going to react according to the legal instruments that we have very early tomorrow morning," Rio 2016 spokesman Mario Andrada said.

The judge's decision blocked organizers from making any payments using public money, under the threat of a fine of 100,000 reais ($31,320) per day.

Andrada declined to say whether the promised money had already been received and spent, citing the court case. He said there were ongoing talks with the government on funding.

"We remain convinced of the will of the government to support us whenever needed and we have negotiations with sponsors that will allow us to finish the Games without any debt and be ready to organize Paralympic Games at the same level," Andrada said.

The organizing committee for Rio 2016 has admitted that a shortfall in funding forced it to cut back on expenditure for the first Olympics to be held in South America.

Organizers have also had to depend on the International Olympic Committee (IOC) making some of its contributions months ahead of the original payment dates.

Asked whether delays in disbursing funds to national Olympic committees could prevent some poorer countries from sending athletes, Andrada said Rio 2016 had been in touch with some countries and would do everything required.

IOC executive director Christophe Dubi said organizers had a contingency fund to help cover unforeseen difficulties, but he said that ticket sales running at around 100,000 per day would help the financial situation of the Games.

Organizers had always expected a belated rush for tickets in Brazil, where locals have a reputation for last-minute purchases.

Andrada said organizers have sold 5.7 million tickets so far, with 800,000 still to be sold.

($1 = 3.1929 Brazilian reais)

(Reporting by Daniel Flynn; Editing by Meredith Mazzilli)