(4)Where the terms of an agreement to refer future differences to arbitration provide that any claims to which the agreement applies shall be barred unless notice to appoint an arbitrator is given or an arbitrator is appointed or some other step to commence arbitration proceedings is taken within a time fixed by the agreement, and a difference arises to which the agreement applies, the Court, if it is of opinion that in the circumstances of the case undue hardship would otherwise be caused, and notwithstanding that the time so fixed has expired, may on such terms, if any, as the justice of the case may require, extend the time for such period as it thinks proper.