New Delhi, May 16 -- Warren Buffett, the towering figure of American finance who built Berkshire Hathaway from a struggling textile maker into a corporate behemoth, has revealed that his decision to step down as chief executive came after finally feeling the effects of his advanced age. In an interview with the Wall Street Journal published on Wednesday, the 94-year-old billionaire investor said he began experiencing the limitations of ageing only in recent years, despite remaining sharp-minded well into his ninth decade. "I didn't really start getting old, for some strange reason, until I was about 90," Buffett told the Journal. "But when you start getting old, it does become - it's irreversible."The announcement of his December departure stunned attendees at Berkshire's annual meeting in Omaha earlier this month, including his designated successor Greg Abel, who was unaware of the impending news despite sharing the stage. Buffett described noticing occasional balance problems and difficulty recalling names as his body began showing signs that convinced him the time had come for leadership transition. "There was no magic moment," Buffett explained in the interview. "How do you know the day that you become old?" The legendary investor pointed to the stark contrast between his capabilities and those of 62-year-old Abel, who joined Berkshire through its 1999 investment in MidAmerican Energy. "The difference in energy level and just how much he could accomplish in a 10-hour day compared to what I could accomplish - the difference became more and more dramatic," Buffett said. Despite stepping down as CEO, Buffett will continue as chairman and maintain an office presence in Omaha. He assured the Journal his decision-making abilities - particularly during market turmoil - remain intact. "I will be useful here if there's a panic in the market because I don't get fearful when things go down in price or everybody else gets scared," he said....