The new charge alleges Antony Piazza attempted to place, or had placed, an object on a plane that was likely to endanger the aircraft or the safety of passengers.
The charge is the most serious of the four against Piazza, an Iranian-born Montrealer who changed his name in the mid-1980s.
Piazza, 71, never made it to his flight as he was stopped at a security checkpoint at Montreal's Pierre Elliott Trudeau airport on Oct. 27.
Piazza was already facing three charges: possession of an explosive substance; attempting to transport an explosive substance on an airplane; and mischief by endangering the safety of an airport or aircraft and disrupting activity at the airport.
"The charges sound similar, but the sentences are different," said Crown prosecutor Alexandre Gautier. "It's far worse, in terms of sentences, than the other charges."
The new charge comes with a maximum prison term of 14 years, Gautier said.
"The new charge relates to the implication of the explosive substance or the thing that could endanger the flight or the safety of the flight," Gautier told reporters. "The first count only related to the fact of bringing onboard the airplane, an explosive substance."
Piazza's bail hearing, scheduled for Tuesday, was postponed until December.
Lawyers have also set aside Jan. 23 and 24 for a preliminary hearing to allow a judge to determine whether there is enough evidence to send him to trial.
Gautier said he's not sure if more charges will come. The investigation is ongoing.
Piazza was trying to board a flight for the United States when the material was detected at a security checkpoint in the U.S. departures area.
His arrest caused lengthy flight delays.
Police also cordoned off a large part of his neighbourhood while sweeping his house.
Authorities have said the luggage contained everything needed to make a bomb, minus the actual explosives.
Piazza chatted with his lawyer in a closed courtroom and complained briefly to the judge Tuesday about not having access to his reading glasses.
A handful of details on the case were made public a few weeks ago by Louis Morena, a defence lawyer initially assigned to Piazza.
He confirmed Piazza, now a Canadian citizen, was born in Iran, that his original name was Houshang Nazemi and that he was convicted of heroin-trafficking in Quebec under his original name in the mid-1980s.
While police and the Crown have remained silent on what exactly was found in Piazza's possession, Morena mentioned some items from the police report, including bullets, powder, wires and lighters. That report indicated Piazza was transporting the carry-on luggage on behalf of another party.
Piazza's new lawyer, Franco Iezzoni, declined to comment Tuesday.