WASHINGTON, United States (AFP) — The US Treasury Department extended on Tuesday a deadline for investors to relinquish their interests in three Russian firms, a move that gives them time to reduce ties with Russian oligarch Oleg Deripaska and ultimately avoid sanctions.

Energy giant En+, aluminum producer Rusal and automotive manufacturer GAZ were included in a sanctions list published in April, which targeted Russian oligarchs close to the Kremlin over allegations of Russian interference in the 2016 US election.

On Tuesday Washington extended until June 6 a deadline for the firms to carry out divestment plans that reduce Deripaska’s interests.

En+ announced last week Deripaska would be reducing his stake to less than 50 percent and resigning from its board of directors.

Rusal is one of the world’s biggest aluminum producers and its inclusion on the list had introduced significant volatility into the market.

US President Donald Trump on April 6 announced sanctions on Russian oligarchs close to President Vladimir Putin following the diplomatic crisis sparked by the nerve agent poisoning of former Russian spy Sergei Skripal in Britain.

Washington accused Deripaska of operating for the Russian government. Other magnates hit by sanctions include the director of state-owned energy giant Gazprom, Alexei Miller.

The company lost billions of dollars from its market capitalisation on fears about its ability to service huge debt obligations.