Mr Forgeard was at the A380's maiden flight in Toulouse in 2005.
French judges have placed Noel Forgeard, the former co-head of Airbus owner EADS, under formal investigation over allegations of insider trading.
Mr Forgeard, who denies wrongdoing, was questioned by two judges over his sale of EADS shares in March 2006 before they slumped by 26% that June.
The fall in value came after serious delays to Airbus's flagship A380 programme were made public.
Investigators want to establish if Mr Forgeard was aware before selling.
"Mr Forgeard has indeed been placed under formal investigation for insider trading by two investigating magistrates after a very long discussion," said Mr Forgeard's lawyer, Jean-Alain Michel.
The former EADS chief was questioned for 36 hours, which ended in the early hours of Friday morning.
Mr Forgeard is reported to have told investigating judges that he had not committed any insider trading and, to his knowledge, neither had any other EADS executives.
EADS has yet to comment, although the firm's current chief executive, Louis Gallois, sent a letter to staff last month in which he spoke of his "confidence in EADS managers in total".
Last month, France's stock market regulator said it had uncovered evidence of insider trading and market abuse at EADS and referred the case to Paris prosecutors.
It did not name any individuals in the findings it made public after the 18-month investigation.
EADS said at the time that it would "exercise vigorously" its right to defend itself.
"EADS will support its managers in their defence, it intends to demonstrate that it has applied standards of excellence when communicating to the market and has acted with full transparency," the consortium said in a statement in April.