London (The Wall Street Journal) -- The world's biggest banking takeover battle began with a letter from a hedge fund with a heartwarming name: The Children's Investment Fund. TCI, as the fund is known, donates a chunk of its profits to charities helping orphans and AIDS victims.

The Feb. 20 letter to the board chairman and chief executive of the largest bank in the Netherlands, ABN Amro Holding NV, alleged they were doing a "terrible" job for shareholders. It demanded that the bank be broken up or sold.