Shareholders, including Air France-KLM which currently owns a 25-percent stake, now have 30 days starting on October 16th to decide whether or not they will subscribe to the new shares.
The shareholders meeting also approved a controversial plan for public Poste Italiane to contribute up to €75 million, which has triggered
accusations of protectionism.
They also said banks Unicredit and Intesa Sanpaolo could take part for up to €100 million.
Alitalia also said its top executives intend to resign once the operation is completed.
The capital increase plan was put together in a hurry under pressure from the government, as energy major ENI threatened to ground the fleet by stopping fuel supplies because of unpaid debts.
Italy has denied that the plan constitutes protectionism and says it will better position Alitalia for an alliance with a foreign partner.
The European Commission has said it is waiting to be formally notified by Italian authorities over the plan to check whether it is state aid.
British Airways' parent company IAG on Monday called on the Commission "to take interim measures to suspend this manifestly illegal aid".