PARIS (Reuters) - The French state has enough cash available from previous share sales to fund the purchase of a 20 percent stake in Alstom , Economy Minister Arnaud Montebourg said on Tuesday. The French state secured an option to buy 20 percent of Alstom from its current top shareholder Bouygues on Sunday, clearing the way for an agreed tie-up between Alstom and General Electric . "Following the sale of (shares in) Airbus , Safran and Aeroports de Paris , we now have over 2 billion euros that will be used to take that stake in Alstom," Montebourg told France's lower house during question time. Shares in Safran, EDF , Orange and Airbus had on Monday been the worst performers on the Paris stock exchange, as traders feared the government would need to sell shares in those companies to fund the purchase. (Reporting by Jean-Baptiste Vey; Writing by Natalie Huet, Editing by dominique Vidalon)