President's shadow

Mauricio Macri, presidential candidate of the Cambiemos (Let's Change) coalition, celebrates with his wife Juliana Awada (behind, in white) after the presidential election in Buenos Aires, Argentina, November 22, 2015. [Photo/Agencies]

A moderate within the Peronist movement, Scioli failed to win over middle-ground voters after struggling to step out of Fernandez's shadow during the election campaign.

His talk of maintaining generous social welfare programs and energy subsidies while making only gradual changes to the capital and trade controls that have hobbled the economy hurt his credentials as a candidate for change.

"Scioli did not manage to differentiate himself from Fernandez and so people stopped seeing him as a change of style and went over to Macri," said political analyst Mariel Fornoni.

The shift in power in Argentina may reverberate across South America where other left-leaning governments, such as Venezuela and Brazil, are also up against the end of a decade-long commodities boom and allegations of financial mismanagement.

Macri was favored by investors and Argentine asset prices were expected to rise on Monday.

"Foreign investors got their wish. Macri's win signals a decisive break with the Kirchner-Fernandez legacy of creditor confrontation and economic mismanagement," said Washington-based emerging markets analyst Gary Kleiman.

"Bond and stock markets will enjoy the afterglow into the new year, but the inherited currency and fiscal mess and direct and portfolio investor antagonism may linger with the Peronists' continued political hold on parts of the government apparatus."

Scioli's apparent defeat amounted to an indictment of Fernandez's stewardship of the economy and her confrontational style.

She often takes to the airwaves to mock her critics with fiery speeches. She denounces holdout creditors suing the country over defaulted debt as "vultures" and invokes the memory of her late husband as the guiding light of her policies.

Fernandez is known as a political fighter committed to her vision of a government actively involved in helping low-income families, and she may return as a presidential candidate in 2019.

She appeared on television in recent weeks appealing to voters to ensure that government funding of education, healthcare and programs for poor mothers remains.