A Milan judge ruled on Wednesday the two companies along with a series of present and past executives would have to face a trial which legal sources said is due to start on March 5.
The case involves the 2011 purchase by Eni and Shell of Nigeria’s OPL-245 offshore oilfield - one of Africa’s most valuable oil blocks - for about $1.3 billion.
Milan prosecutors allege bribes were paid to win the license to explore the field which has never entered into production.
Besides the two companies, Eni CEO Claudio Descalzi and former Shell Foundation Chairman Malcolm Brinded were sent to trial along with 11 other people, the sources said.
Under Italian law a company can be held responsible if it is deemed to have failed to prevent, or attempt to prevent, a crime by an employee that benefited the company.
Shell said it was disappointed by the outcome of the hearing but added it believed the judges would conclude there was no case against the group or its former employees.
“There is no place for bribery or corruption in our company,” it said.
State-controlled Eni reiterated the company and its CEO had done nothing wrong, adding the board fully backed Descalzi who at the time of the deal was head of exploration and production (E&P).
Brinded, a former E&P director at Shell, said he had done nothing wrong, adding there was no basis for the charges.
The OPL-245 license was initially awarded in 1998 by former Nigerian oil minister Dan Etete to Malabu Oil and Gas, a company in which he held shares. It was then sold to Eni and Shell.
Campaign group Global Witness and others say much of the $1.3 billion in payments for the block did not go to the state but instead went to Etete, convicted of money laundering in a 2007 French case related to his time in the Nigerian government.
Shell has previously said it was aware that some of the payments it made to Nigeria for rights to the oilfield would go to Malabu but said the transaction was fully legal.
The Italian inquiry is one of several under way into the acquisition of OPL-245, including cases in the Netherlands and Nigeria.
Additional reporting and writing by Stephen Jewkes; editing by Jason Neely and David Evans