A former CEO of a trillion dollar investment firm has revealed that his decision to resign was motivated by his failure to attend important milestones in his young daughter’s life due to his busy work schedule.

Mohamed El-Erian, who quit his job as chief of PIMCO last year, wrote that when his daughter handed him a list of events he had missed - including her first day of school – he was prompted to step down.

The California-based businessman was earmarked as successor to the company’s founder Bill Gross. As CEO, he kept gruelling hours - sleeping from 9pm-1am, writing until 4.30am to then working on the trading floor for five hours and arriving at his office at 9am.

In an essay for Worth in June, El-Erian, 56, explained his decision. He writes: “About a year ago, I asked my daughter several times to do something - brush her teeth, I think it was - with no success.

He then explains, “She asked me to wait a minute, went to her room and came back with a piece of paper. It was a list that she had compiled of her important events and activities that I had missed due to work commitments. Talk about a wake-up call.

The list contained 22 events - from her first day at school and first soccer match of the season to a parent-teacher meeting and a Halloween parade – due to his work commitments.

He added: “But it dawned on me that I was missing an infinitely more important point. As much as I could rationalize it - as I had rationalized it - my work-life balance had gotten way out of whack, and the imbalance was hurting my very special relationship with my daughter. I was not making nearly enough time for her.”

El-Erian, who was educated at Cambridge University, still remains in his role in Allianz as chief economic advisor, where he now spends 50 per cent of his time.

While he regrets the controversy surrounding his dramatic departure, El-Erian believes a part-time role in the company would have been “inconsistent” with his style of management, he told Reuters recently.