SHARE

The former chairman and chief executive of Morgan Stanley, John Mack, resigned from the board of Russia’s Rosneft, the company said Thursday.

Mack, 69, left the Rosneft board after serving less than a year.

The United States imposed sanctions on Rosneft’s chief, Igor Sechin, in late April because of Russia’s role in Crimea.

Rosneft said Mack’s decision to leave wasn’t related to the sanctions, according to a Reuters report.

“He left for personal reasons,” a spokesman for Rosneft said.

State-controlled Rosneft is Russia’s biggest oil producer.

The company said Artur Chilingarov, 74, has been proposed to replace Mack on the board.

Chilingarov is a member of Russia’s upper house of the parliament and earned a reputation for his exploration of the Arctic, Reuters said.

Mack joined Rosneft’s board last June after the company acquired TNK-BP for $55 billion from BP and the AAR (Russia) consortium.

In January this year, Rosneft announced plans to buy control of Morgan Stanley’s global oil trading operations.

Rosneft said most recently the Morgan Stanley deal will close later this year.