The tragedy unfolded when a freight train derailed at Viareggio and the gas it was carrying exploded into a fireball engulfing the station and nearby areas of the coastal Tuscan town.
Prosecutors had requested 16 years for Moretti, now CEO of defence and aerospace giant Leonardo, and 15 for Elia.
Shares in Leonardo dropped 3.4 per cent on the Milan bourse on the news of Moretti's conviction.
In total 33 individuals and nine companies were tried on various charges including rail disaster, multiple manslaughter, culpable fire and culpable injuries.
The court made 10 acquittals in the trial. Moretti was convicted in his capacity as former RFI CEO but acquitted as former FS CEO, his lawyers explained on Tuesday. FS and FS Logistica were among the companies acquitted, while RFI and Trenitalia were found guilty.
Moretti's lawyer Armando D'Apote described the verdict as a "scandalous outcome of the trial and I stress the fruit of the populism that oozes from the sentence".
However, he voiced "partial satisfaction" that Moretti had been acquitted in his former capacity as FS CEO, and at the acquittal of FS itself.
Victims' relatives applauded briefly after the sentence but said they would comment on the verdict on Wednesday.
Meanwhile former Viareggio mayor Luca Lunardini said the ruling had "provided some comfort".
"The judges' decision shows what we always said: that it was not a natural event but caused by Man," Lunardini added.
He said Viareggio was not "seeking revenge, but justice" from the court.
"Certainly, the prosecutors' requests were higher and the sentence has been halved, and that leaves us a little perplexed; but you don't comment on sentences, you respect them."
Separately, Tuscany regional Governor Enrico Rossi stressed the importance of the sentence not timing out under the statute of limitations.
"It's important that it all hasn't already timed out, and I think this sentence corresponds to a need for justice, raised with much firmness and force by the victims and the entire city of Viareggio," he said.
"As a region we were civil plaintiffs in this trial and so we behaved as it was fit and proper to do.”
Rossi concluded by paying tribute to the lives lost in the disaster.
"It was a real tragedy which will be remembered over time, and I don't think anyone can really heal the wound that that dramatic event brought on the city."
With ANSA
