The move came after blacklisted billionaire Oleg Deripaska took action to sharply cut his stake in the companies. The tycoon is known to have friendly relations with Russian President Vladimir Putin and had business ties with U.S. President Donald Trump's former campaign chairman Paul Manafort, who was convicted in Special Counsel Robert Mueller's investigation into Russian meddling in the 2016 election.
Deripaska is one of several oligarchs sanctioned last year in retaliation for what the U.S. called "the Russian government's ongoing and increasingly brazen pattern of malign activity across the world," citing its interference in Syria and its seizure of Crimea.
Rusal, EN+ Group Plc and EuroSibEnergo JSC have "reduced Oleg Deripaska's direct and indirect shareholding stake... and severed his control," the Treasury's Office of Foreign Assets Control (OFAC) said in a statement.
"The companies have also agreed to unprecedented transparency for Treasury into their operations by undertaking extensive, ongoing auditing, certification, and reporting requirements."
The delisting -- first announced in December -- came as the companies sought to avoid being locked out of global markets due to their close association with Deripaska.
The sanctions banned Americans and organizations with U.S. divisions, such as many global banks, from doing business with the companies and froze Deripaska's personal assets in U.S. jurisdictions.
"All sanctions on Deripaska continue in force," the OFAC said.