The Children's Investment Fund Management founder Christopher Hohn and his wife, Jamie Cooper-Hohn, have begun divorce proceedings.
The couple, who met at Harvard Business School in the early 1990s, have been separated since earlier this year. The couple has four children, including 12-year-old triplets.
Jamie Cooper-Hohn has run the charity that gave TCI its name, and she and Hohn have donated more than US$2 billion to philanthropic efforts. But TCI in March said it would end its practice of donating a portion of its fees to the foundation, saying it had become "large enough."
In June, a friend of the couple told The Telegraph that the two "are living separate lives," adding, "It's very sad."