Both the Lagardere media group and Daimler are withdrawing from EADS to focus on core businesses, with the German government picking up part of Daimler’s stake to preserve Franco-German balance in EADS.
Enders pledged to prevent the buyback penalizing future growth, capital investment or a dividend policy which he said would be significantly more attractive than in the past.
The aerospace group left open its options on how to implement the buyback, whose potential value has risen sharply since it was first announced in December, igniting a 39 percent rally in the share price since the start of this year.
But following recent price gains, Enders said he would not launch a buyback worth more than a third of its net cash, suggesting an operation worth some 1 billion euros less than the full allowance.
EADS had net cash of 12.29 billion euros at the end of 2012.
France and Germany will hold core stakes of 12 percent each in EADS, with Spain at 4 percent.
A special non-voting foundation has been set up to hold any surplus government shares to avoid crossing the 30 percent threshold for a mandatory bid under Dutch law.
But EADS shares fell 3 percent after the company said Spain would take advantage of the changes to sell most of its surplus, or 1.15 percent of EADS, more quickly than expected in a move likely to raise around 400 million euros.