Argentina and its main holdout creditors have reached a $4.653 billion US agreement in principle to settle a 14-year-old sovereign debt default dispute, a deal that could help the country to return to international capital markets and revive its economy.

The deal, agreed to late on Sunday and announced by the New York court-appointed mediator Daniel Pollack on Monday, will see the four largest remaining holdout creditors get paid 75 percent of the amount outstanding on their full judgments, including principal and interest.

"It is) a very concise business agreement with legal implications that took a great deal of time and effort and intense discussions over a period of weeks to arrive at," Pollack told reporters at a press conference where he summed up the ten-paragraph agreement.

Pay by April 14

"The agreement in principle is terminated unless parties otherwise agreed if payment does not occur by April 14, 2016 at 12 noon ET," he added.

Hedge fund Elliott Management, run by Paul Singer, brought numerous lawsuits against Argentina over the course of the dispute, with hearings before U.S. District Judge Thomas Griesa, that were appealed but failed to gain a hearing before the U.S. Supreme Court.

The remaining largest holdout investors include Aurelius Capital Management, run by former Elliott alumni Mark Brodsky, as well as Davidson Kempner and Bracebridge Capital.

The deal "closes a chapter by putting an end to the debt default saga which limited Argentina's access to international capital markets," said Alberto Ramos, chief Latin America economist for Goldman Sachs, predicting that it would also lead to an influx of investment in Argentina.

The debt conflict goes back to Argentina's 2001-2002 financial collapse, when it defaulted on $100 billion in debt. Most creditors renegotiated in 2005 and 2010 bond swaps.

Hedge funds take Argentina to court

But a group of creditors led by billionaire hedge fund manager Singer refused and took Argentina to court in New York.

A New York judge refused to allow Argentina to make the reduced payments to its other creditors, unless it first made full payments to the holdout bondholders. The legal saga involved years of court battles, street protests in Buenos Aires, the seizure of an Argentine naval vessel, and increasingly distorted economic policy as the government tried to avoid settling with the holdout creditors. 

The deal is a boost for President Mauricio Macri, who assumed power in December after campaigning on promises to modernize South America's second-largest economy by solving the dispute and attracting foreign investment.

"It gives me greatest pleasure to announce that the 15-year pitched battle between the Republic of Argentina and Elliott Management, led by Paul E. Singer, is now well on its way to being resolved," said arbiter Daniel A. Pollack in a statement.

Needs support of Congress

The agreement still must be approved by Argentina's Congress, which would also need to revoke two laws that effectively ban such settlements.

The "Lock Law" prevents Argentina from offering one group of creditors a better deal than others and the "Sovereign Payment Law," passed in 2014, allowed Argentina to pay creditors with renegotiated debt in the face of a New York court order not to do so.

The 2014 law was passed at the behest of former President Cristina Fernandez, who refused to negotiate with groups she called "vultures," casting the fight as an American court trying to bully a sovereign nation.

With files from the Associated Press