Government as shareholder. Auction notice for participation in SANEPAR (controlled by the State of Paraná) providing for a shareholders' agreement with an arbitration clause. Lawsuit seeking nullity of the shareholders' agreement on the grounds that it would affect the State of Paraná's control over SANEPAR. Discussion on the legitimacy of the Executive Branch to establish the arbitration clause. Compliance with the limits of the authorization under Law No. 11.963/97. Objection based on an arbitration agreement dismissed: