The banks within a district may merge into a single entity (hereinafter in this subchapter referred to as a “merged bank”) if the plan of merger is approved by—

((1)) the Farm Credit Administration Board;

((2)) the respective boards of directors of the banks involved;

((3)) a majority of the stockholders of each bank voting, in person or by proxy, at a duly authorized stockholders’ meeting with each association entitled to cast a number of votes equal to the number of its voting stockholders; and

((4)) in the case of a bank for cooperatives, a majority of the total equity interests in such merging bank for cooperatives (including allocated, but not unallocated, surplus and reserves) held by those stockholders or subscribers to the guaranty fund of the bank voting.