*

US judge orders Argentina to relinquish 51% stake in YPF

*

Argentina government says will appeal ruling

*

YPF leads development of major Vaca Muerta shale region

*

Argentina pushing shale production to bring in exports

dollars

*

Legal standoff could hit aims to return to global markets

(Adds comments from analysts Monteverde and Bronstein,

paragraphs 12-13, 15-16)

By Eliana Raszewski, Leila Miller and Jorge Otaola

BUENOS AIRES, July 1 (Reuters) - A dramatic ruling by a

U.S. court ordering Argentina to hand over the 51% stake it

holds in state energy firm YPF has cast a shadow over

the country's plans for its huge Vaca Muerta shale formation and

hopes to return to global markets.

U.S. District Judge Loretta Preska said on Monday that Argentina

must transfer its YPF shares within 14 days to partially satisfy

an earlier $16.1 billion court judgment against the country over

its 2012 nationalization of the firm.

The government of pro-market libertarian Javier Milei said

it would appeal the ruling to "defend national interests."

The judgment adds uncertainty to Argentina's plans to turn

Vaca Muerta, the world's No. 2 shale gas reserve and No. 4 for

shale oil, into a key global energy-producing region that would

help bring in foreign currency needed to prop up the economy.

YPF leads development of Vaca Muerta, often partnering with

other local and international firms including Shell and

Chevron ( CVX ). Vaca Muerta has hit production of over 400,000

barrels per day of oil and some 70 million cubic meters of gas

per day.

"Control of YPF is important for Milei; that's why an appeal is

the only option for him," said Marcelo Garcia, director for the

Americas at New York-based risk consultancy Horizon Engage. "It

should bring in the U.S. dollars the economy lacks."

The legal dispute arose from Argentina's 2012 seizure of the 51%

YPF stake held by Spain's Repsol, without tendering for

shares held by minority investors Petersen Energia Inversora and

Eton Park Capital Management.

In 2023, Preska awarded $14.4 billion to Petersen and $1.7

billion to Eton Park in the same case, which Argentina is also

appealing. The plaintiffs are represented by litigation funder

Burford Capital, which expects to receive some 35% and

73% of Petersen's and Eton Park's respective damages.

LEVERAGE TO NEGOTIATE

The legal ruling could also dent Argentina's ability to tap

global markets, something the country is keen to do to bolster

its depleted reserves after years of currency crises, regular

fiscal deficits draining state coffers and high inflation.

"These unresolved disputes could hinder, or even block,

Argentina's return to the international capital markets,"

BancTrust & Co said in a note on Tuesday.

Argentine economist Agustin Monteverde said the uncertainty

could also limit YPF's own fundraising and strategic planning.

"A firm whose majority shareholder is unclear is in the

midst of a crisis; it's difficult to make decisions," he said.

Analysts and officials pointed out that surrendering the

shares in YPF would constitutionally need the approval of

Argentina's Congress, which was unlikely to happen. A more

realistic outcome was that it would force Milei to negotiate.

"I find it unthinkable that a vulture fund would take over

51% of YPF's shares," said Victor Bronstein, director of the

Center for Energy, Politics, and Social Studies and a professor

at the University of Buenos Aires.

"This ruling allows them to negotiate, because I don't

really think they are interested in being YPF shareholders."

Argentina's government must urgently build up foreign currency

reserves to pay its debts and meet targets as part of a $20

billion loan program agreed with the International Monetary Fund

in April, the indebted country's 23rd IMF program.

YPF's U.S.-listed shares slumped more than 5% on Monday,

while Burford's stock price jumped. Both steadied on Tuesday.

YPF's current market capitalization is around $12.5 billion.