BUENOS AIRES, Argentina (AP) -- In a bold move to gain control of Argentina's energy reserves, President Cristina Fernandez pushed forward a bill to renationalize the country's largest oil company on Monday despite fierce criticism from abroad and the risk of a major rift with Spain.

In a national address, Fernandez said the legislation put to congress would give Argentina a majority stake in oil and gas company YPF by taking control of 51 percent of its shares currently held by Spain's Repsol.

Both Repsol and Spain strongly oppose the move and have warned that it could turn Argentina into an international pariah.

YPF is vital for Argentina's energy future, especially after its recent find of huge unconventional oil and natural gas reserves. But the company is under pressure from Fernandez's government to raise output while its shares have plunged in recent months on fears of possible state intervention. Argentina this year expects to import more than $10 billion worth of gas and natural liquid gas to address an energy crisis even though it is an oil-producing nation, according to estimates from the hydrocarbon sector.

``We are the only country in Latin America, and I would say in practically the entire world, that doesn't manage its own natural resources,'' Fernandez said. She said her proposal ``is not a model of statism'' but ``the recovery of sovereignty.''

Critics blame the government for an energy shortage and high gasoline prices. But Fernandez said the shortage is the result of Repsol's ``emptying'' of YPF, and that Argentina had a deficit of $3 billion last year partly due to energy imports.

Argentines gathered in Buenos Aires' main square shouting slogans, waving national flags and carrying banners supporting the government takeover. One of them read: ``Today, with Cristina, we recovered YPF.'' YPF was privatized in the 1990s. Repsol's subsidiary in Argentina holds 57 percent of YPF's shares.

Fernandez said the renationalization was a long-held desire of her late husband and predecessor, former President Nestor Kirchner.

``I hope he's watching over me because he always wanted to recover YPF for the country,'' she said.

But analysts said the planned takeover risks alienating foreign investors and prompting retaliation from Spain's government.

``It is a bad decision,'' said Emilio Apud, a former Argentine energy secretary who now works as a consultant. ``It gives the Argentine government a bad image'' and will discourage investment, he said. Apud also called the proposed law ``a bad way to treat friendly governments like Spain.''

In Madrid, Spanish Foreign Minister Jose Manuel Garcia-Margallo called the move arbitrary, and said it broke the climate of cordiality and friendship that had existed with Argentina. He said Spain would respond with ``forceful measures'' he did not describe.

The European Commission has warned that nationalizing YPF would be bad for the investment climate in Argentina, and has said it backs Spain in the standoff over the subsidiary.

Fernandez, however, was unmoved by the risk of a row with Spain, Argentina's largest foreign investor.

``This president is not going to answer any threat, is not going to respond to any sharp remark.,'' she said to applause from business, union and political leaders.

``I am a head of state and not a hoodlum,'' said Fernandez, who has also renationalized the country's Aerolineas Argentinas airline and nationalized the Anses state private pension funds.

There was no explanation of how, or how much, Repsol and its stockholders would be compensated. Analysts say that the government might have to use Central Bank reserves, or funds from the Anses to pay for the takeover.

``The issue that scares investors is not knowing how far the governmental participation will go, if it's only YPF or if it is going to include other petroleum companies in Argentina,'' said Joe Amador, Latin America director for Scotia Waterous, the oil and gas arm of Scotiabank, in Houston, Texas.

Even with its share prices depressed, YPF last week was valued at $13.6 billion, and buying half of that would deplete Argentina's treasury of funds it needs to maintain the populist subsidies that have kept the country's economy afloat.

Repsol released a statement promising to protect the interests of its shareholders. It called the move ``unlawful and gravely discriminatory.''

Spanish officials had earlier protested the plan, saying Argentina risks becoming ``an international pariah'' if it takes control of Repsol' subsidiary, Repsol YPF SA

Spain's foreign minister last week summoned Argentine Ambassador Carlo Antonio Bettini to convey concern over possible nationalization of YPF, which represents 42 percent of Repsol's total reserves, estimated at 2.1 billion barrels of crude.

Mexico's Economy Minister Bruno Ferrari said in recent days that Spain had requested that Mexico intervene in the row with Argentina over Repsol-YPF SA. But Ferrari said Mexico's role in the dispute is still to be determined.

``We will hold talks with Spain over the next days to exactly determine what Mexico can do,'' he said ahead of the World Economic Forum on Latin America 2012 that will be held in the coastal city of Puerto Vallarta.

At the forum on Monday, Mexican President Felipe Calderon criticized Argentina's move, calling it ``not very responsible and not very rational.''

In contrast, Venezuela's foreign ministry issued a statement voicing support for Fernandez's decision to renationalize YPF. Venezuela's state oil company also supported the Argentine decision and said it is willing to help strengthen Argentina's oil industry,

``Venezuela puts all its technical, operational, legal and political experience of Petroleos de Venezuela at the disposition of the government of Argentina and its people to strenthen the state oil sector,'' the foreign ministry said.

Governors of oil-producing Argentine provinces have withdrawn about 15 oil leases, representing 18 percent of YPF's crude production, alleging the company failed to keep its promises to develop them. YPF has countered that it has invested millions in those areas and plans to increase production, but Argentine officials have said that still falls short.

How Argentina may try to displace Repsol has been the subject of wide speculation since the government's pressure campaign began in February.

The president's proposal would leave Repsol with just a little more than 6 percent of YPF's shares.

Fernandez put Federal Planning Minister Julio de Vido and Economics Vice Minister Axel Kicillof in charge of handling the expropriation.

The president's proposal declares that the exploration and exploitation of hydrocarbons is ``of national public interest'' and declares that building up the nation's supply is a priority.