Airbus parent company EADS will launch a probe into the latest delays of the superjumbo A380, its co-chairman said in an interview published Thursday, amid mounting questions about the company's management and stock sales earlier this year.

Arnaud Lagardere, co-chair of European Aeronautic Defence & Space Co., said he had no knowledge of the production problems with the A380 — the world's biggest passenger plane — until Airbus made an announcement Tuesday, according to the newspaper Le Monde.

Lagardere said EADS would launch a probe to determine what caused the delays and how much Airbus co-Chief Executive Gustav Humbert and EADS' co-Chief Executive Noel Forgeard knew about the problems.

Speculation is rife that the debacle could cost them their jobs. Forgeard, who launched the A380 project as head of Airbus in 2000, on Wednesday deflected suggestions that the setback could lead to his ouster.

The mounting clamor to discover who knew what and when suggests serious fractures within the management of EADS, a showcase European project jointly led by French and German management.

EADS spokesman Michael Hauger said in Frankfurt that Airbus had informed EADS management and customers in mid-April about possible delays with the A380, but at that point the extent of the delays could not be determined.

The news comes amid revelations that Forgeard and his family and other top EADS managers sold off shares before Airbus announced the delays, which sent the company's stock tumbling and angered airlines worldwide.

Shares in EADS plunged more than 25 percent Wednesday after the delay and a profit warning, shaving millions of dollars off the company's value. Stock prices rallied slightly Thursday morning, up 4.1 percent to 19.50 euros ($24.50).

They remained well below the price of mid-March, when Forgeard, his family and other managers sold off large packets of shares, according to filings with France's stock market regulator AMF.

Forgeard exercised 2.5 million euros ($3.1 million) worth of options at 32.01 euros ($40.21), and three of his children each sold 1.4 million euros ($1.75 million) worth of shares in the same period, at 32.82 euros ($41.23), according to the regulator. Board members Francois Auque and Jean-Paul Gut also sold shares.

Lagardere's company, Lagardere SA, also sold half of its 15 percent stake in EADS earlier this year, but he insisted that he had no idea of the A380's troubles until this week.

"We had no information," he was quoted in Le Monde as saying. "If we had been dishonest, we would not have sold 7.5 percent but all of our shares."

EADS said Forgeard's share sales were not informed by the A380's production delays and that all the transactions by management fully meet the company's compliance rules. Board members have only three weeks each quarter when they can trade their shares, EADS said.

A representative declined to comment further and would not say whether the sales were on a predetermined schedule.

"All of this seriously hurts the image of this European jewel" and "sharpens the teeth of Boeing," the daily Liberation wrote Thursday. "And it gives a bit of grist for the mill ... for the bards of Euroskepticism."

The production delays raised questions about the A380's future, as rival Boeing Co. (BA) is staking its bets on a smaller, more fuel-efficient model.

Airlines worldwide demanded compensation, reconsidered orders — and crucial customer Singapore Airlines slapped Airbus in the face with a deal Wednesday for 20 Boeing 787-9 aircraft worth $4.52 billion. Airbus had hoped Singapore would buy the A350, a planned competitor to the 787 that has been plagued with problems.

Airbus had a small boost Thursday, however, from a deal with Chinese flag carrier Air China Ltd. to buy 24 Airbus A320 aircraft, as part of a package involving the purchase of 150 Airbus jetliners by mainland airlines.