Exectives of the firm that owns Airbus face allegations that they used information on the "superjumbo" project to their advantage. They deny the charges and say they're sure of acquittal.
Bosses sold shares before delays to the Airbus A380 project were announced
Bosses have been giving evidence over their alleged involvement in inside trading in Europe's Airbus "superjumbo" project.
Altogether, 17 former and current executives along with three companies face accusations in what is being seen as Europe's highest profile case of insider trading in years.
Individuals who arrived at the hearing on Monday face tough fines if they are convicted while the companies, which include Germany's Daimler car firm, also face sanctions.
The accused are alleged to have sold stock in the European Aeronautic Defence and Space Company (EADS) when they knew that the price was set to plummet. Sales were made in March, 2006, when stock options were around 30 euros each, their historic high.
Airbus boss Tom Enders said he was confident of being proved innocent
Prices slumped after sales
It is claimed that the executives already knew about delays to the company's Airbus A380 project, and used that information to their advantage. The prices slumped by 26 percent in just one day when the delay was officially announced in June.
Airbus employs around 52,000 people and has sites in Germany, France, the UK and Spain.
The hearings, being held by the French Financial Markets Authority AMF in the former home of the Paris stock exchange, follow a 30-month probe and are not open to the press or public. The AMF itself is under pressure to show that it can be tough on big business.
Executives could be made to pay fines as high as 5.45 million euros if they are convicted.
Among those facing allegations is former EADS co-chairman Noel Forgeard, who said that he felt "serene" when he arrived in court.
Airbus workers in Hamburg celebrate the delivery of a newly-built A380
Lawyers are confident
Forgeard, who faces the highest fine, earned 3.5 million euros when he sold the options. His lawyers claim that he can show that his stock was sold before problems were noticed with the A380 project.
Current chief executive of EADS's Airbus project Thomas Enders also said that he was also sure that he would be cleared. Previously, Enders has declared that the probe was biased and driven by conspiracy theories.
The hearings come three days after the first of Air France's A380s made its inaugural flight from Paris to New York. The giant double-decker aircraft made its maiden journey with Singapore Airlines in October 2007, form Singapore to Sydney.
In addition to investigating the accusations against EADS, the hearings are also dealing with cases against Daimler, which was DaimlerChrysler at the time, and Lagardere, a French media group in which the state is a shareholder.
Editor: Michael Lawton