Led by Ouassini Cherifi, known as "The Turk," the defendants are charged with a failed raid on a cash delivery company in 2005 and robbing France's official printing operation, France 24 reported. They deny the charges.
The gang allegedly operated out of Cherifi's restaurant in the Clichy-Sous-Bois suburb of Paris, prosecutors say.
Acting on information from one of the suspects, police found dynamite, an AK-47, a French military rifle, handguns, hundreds of rounds of ammunition, a radio transmitter, police uniforms and bulletproof vests in a nearby garage.
Cherifi, 36, is accused of meeting Islamic extremists in Turkey in September 2005 and promising to fund them through his crimes. He had been convicted in 2002 of sending fake passports to radicals but was released on parole.
Some of the suspects allegedly have admitted being part of a criminal group, but all deny acting to raise cash for terrorists.
The case is being tried before a special national security court made up entirely of judges.