Italy's Supreme Court threw out an appeal from Shell and four former Shell managers. The appeal was aimed at halting the Malabu corruption trial.
The trial also involves Eni's chief executive, legal sources told Reuters.
The long-running case on alleged corruption in Nigeria, revolves around the 2011 purchase by Eni and Shell of Nigeria's OPL-245 offshore oilfield for about $1.3 billion (974.3 million pounds).
The local press refers to the case as the 'Malabu oil scam'.
Malabu and Dan Etete
Dan Etete was a former petroleum minister in Nigeria during the reign of late General Sani Abacha. In 1998, he formed Malabu Oil Limited and acquired ‘OPL 245’ just five days after incorporating the company with no employee.
For the rich oil bloc, Etete only paid $2 million out of the $20 million legally required by the state. In 2011, Malabu Oil Limited sold OPL 245 to Shell and Eni for $1.3 billion.
The deal was facilitated by JP Morgan Chase.
ALSO READ: Nigeria sues JP Morgan over Malabu oil deal
Malabu was sold to Shell and Eni for $1.3billion during the Goodluck Jonathan administration in 2011.
Shell and Eni did not want to deal directly with Etete who had been convicted in France for his part in a separate money laundering scandal, so they wired the money to an account belonging to the federal government of Nigeria domiciled with JP Morgan bank, London.
The Malabu trial in Italy commenced in May, with the next hearing slated for June 20.
Shell’s appeal was aimed at reversing the trial to the preliminary hearing stage due to what the oil company said were procedural errors, but the court decided the appeal was inadmissible, Reuters writes.
According to Reuters, Nine current and former executives or contractors, including Eni Chief Executive Claudio Descalzi, have been accused by Italian prosecutors of paying bribes to secure the license to explore OPL-245.
OPL-245 is one of Nigeria’s richest oil wells with an estimated 9 billion barrels of oil.
OPL-245 has never been commercially explored; no thanks to litigation.
Shell and Eni have denied any wrongdoing.
If found guilty, those on trial could face jail.
A Shell spokeswoman told Reuters on Wednesday that; "based on our review of the prosecutor of Milan's file and all of the information and facts available to us, we do not believe that there is a basis to convict Shell or any of its former employees."