BUENOS AIRES--The International Monetary Fund said it will stand by Argentina after the government authorized currency controls on Sunday in an about-face by President Mauricio Macri, who had previously lifted many protectionist practices of his predecessor, Cristina Fernandez de Kirchner.

  The central bank is now authorized to restrict purchases of dollars as it burns through its reserves in an effort to prop up the peso currency, the government said in a decree published in its official bulletin. The measure means companies will need permission from the central bank to access the foreign exchange market to purchase foreign currency and make transfers abroad.
  The government of Latin America's third largest economy said in the decree that "the executive branch needed to adopt a series of extraordinary measures aimed at ensuring the normal functioning of the economy."
  Hours after the decree was published, a spokesman for the IMF, with which Argentina has a $57-billion standby agreement, said Fund staff was analyzing Argentina's "capital flow management measures with the aim of protecting exchange rate stability and the savers."
  "Staff will remain in close contact with the authorities in the period ahead and the Fund will continue to stand with Argentina during these challenging times," the spokesman said.
  After opposition candidate Alberto Fernandez and Fernandez de Kirchner, who is now his vice presidential candidate, pulled off a stunning upset in the Aug. 11 primary vote, bonds, stocks and the peso currency plummeted on market fears over a potential return to the interventionist policies of Fernandez de Kirchner's previous government. Macri's government and the central bank are trying to stabilize the economy as the Oct. 27 presidential election looms, for which Fernandez is now the front-runner.
  The central bank has burned through nearly $1 billion in reserves since Wednesday in an effort to prop up the peso. But the intervention did not have the desired impact and risk spreads blew out to levels not seen since 2005, while the local peso currency extended its year-to-date swoon to 36%.
  The central bank said in a statement that the measure did not limit people from withdrawing dollars from their accounts. It does, however, restrict people from buying more than $10,000 a month, or making transfers exceeding that amount per month.
  It also requires exporters to liquidate their foreign exchange earnings in the local market under deadlines. Companies will not be permitted to stockpile dollars, the bank said.
  "Trade is not restricted. There were restrictions before, but there are none now," said a source familiar with the new central bank measure.
  "All of this is to preserve the economy as well as possible in this circumstance," said the source, who requested anonymity because he was not authorized to speak to the media.