Humbert, 58, was released on bail of €350,000 after having been charged by Judges Xaviere Simeoni and Cecile Pendaries, the source said. He had been questioned in custody since Monday.
Former EADS chief executive Noel Forgeard and the company's former general manager, Jean-Paul Gut, have already been charged in the probe although both have denied any wrongdoing.
The French financial market regulator, AMF, in April said in a report that Humbert had sold 160,000 shares in the European Aeronautic Defence and Space Company in November 2005, earning €1.685 million.
The German, who took over Airbus in June 2005 and resigned in July 2006, is suspected of having benefited from privileged information on the financial picture at Airbus.
Humbert's lawyer, Nicolas Morvilliers, insisted that such suspicions were "unfounded" and said his client would make use of subsequent legal proceedings to defend himself.
In total 17 French and German members and former members of EADS and its main subsidiary, Airbus, are suspected of insider trading by the French regulator.
These include the present head of Airbus, German Thomas Enders, the French head of a space engineering subsidiary EADS Astrium, Francois Auque, and another Airbus manager, Fabrice Bregier, formerly chief executive of Eurocopter.
Forgeard, 61, who stepped down in July 2006, was released on May 30 after posting bail of one million euros. He made €4.3 million with the sale of 360,000 EADS shares, held in stock options.
Gut, 46, who left EADS in June of last year, allegedly sold €1.7 million in shares just months before Airbus revealed production delays with the A380 superjumbo.
He was charged with insider trading in mid-June and released on bail of €400,000.
If convicted, both men face up to two years in jail and a fine of up to 10 times the amount gained through the alleged insider trading.
The announcement in June 2006 of a six-month production delay on the new A380, the world's largest airliner, threw EADS and its aircraft unit into crisis.
The EADS share price fell 26 percent on the stock market and Airbus launched a restructuring programme to shed 10,000 jobs.
Despite its problems, EADS reported a robust return to profit in May. Butit also acknowledged new delays, the fourth in two years, in A380 deliveries.
It announced a first quarter net profit of €285 million, exceeding analyst forecasts.
Singapore Airlines put the first A380, able to carry some 850 passengers, into commercial service in October.