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.

US judge orders state to turn over its controlling stake in state-run oil company YPF SA as partial payment of a US$16-billion court judgment.

US District Judge Loretta Preska in Manhattan said on Monday that Argentina must transfer its 51% stake in YPF within 14 days to Bank of New York Mellon, and instructed the institution to transfer the shares within one business day to the plaintiffs.