By Andrew Osborn and Gleb Stolyarov

MOSCOW (Reuters) - Two Moscow airport workers involved in a plane crash in which Christophe de Margerie, the CEO of Total, was killed had been drinking alcohol, Russia's aviation regulator said on Tuesday, saying the accident could have been avoided altogether.

The French energy group's chief executive was killed along with his jet's three-person crew in October 2014 at Moscow's Vnukovo airport when they tried to take off for Paris but collided with a snow plough that had strayed onto the runway.

De Margerie oversaw multi-billion-dollar Total investments in Russia and was killed just as the conflict in Ukraine raised tensions with the West to levels not seen since the Cold War and brought down Western sanctions on Russia.

The snow plough driver, Vladimir Martynenko, and a duty engineer, Vladimir Ledenev, both pleaded guilty to causing de Margerie's death in July.

Russia's Interstate Aviation Committee (IAC) said on Tuesday it had completed its own investigation and that Martynenko and the airport's duty shift supervisor, whom it did not name, had been drinking alcohol and were partly to blame for the tragedy.

It said Martynenko had suffered "a loss of situational awareness" and that the shift supervisor had not done his job properly. Alcohol had been found in both men's blood, it said.

But the IAC said the accident could probably have been avoided altogether if the jet's crew had aborted take-off once they had spotted the snow plough on the runway rather than pressing ahead.

"A simulated test showed that if the crew had decided to abort take-off at that stage and used all available braking methods ... it would probably have been possible to avoid the catastrophe," the IAC said in a report.

"The lack of a decision to abort take-off was probably the result of the far from ideal psychological and emotional state of the crew which could have made it hard for the crew to assess the real threat level," the IAC said.

This was a reference to the fact that they had been waiting for a long time at an unfamiliar airport and wanted to return home as soon as possible.

The IAC said it had drawn up new safety recommendations based upon its investigation.

(Editing by Richard Balmforth)