(1) ¹[The mandate of an arbitrator shall terminate and he shall be substituted by another arbitrator, if]—
         (a) he becomes de jure or de facto unable to perform his functions or for other reasons fails to act without undue delay; and
         (b) he withdraws from his office or the parties agree to the termination of his mandate.
     (2) If a controversy remains concerning any of the grounds referred to in clause (a) of sub-section (1), a party may, unless otherwise agreed by the parties, apply to the Court to decide on the termination of the mandate.
     (3) If, under this section or sub-section (3) of section 13, an arbitrator withdraws from his office or a party agrees to the termination of the mandate of an arbitrator, it shall not imply acceptance of the validity of any ground referred to in this section or sub-section (3) of section 12.