Billionaire philanthropist MacKenzie Scott has reduced the size of her stake in Amazon.com by 42 per cent since last year, Bloomberg News reported on Tuesday, citing a regulatory filing. Scott, the former wife of Amazon founder Jeff Bezos, holds 81.1 million shares in the company, according to the latest disclosure dated September 30, down 58 million from a year ago, according to the news report. Based on Amazon's closing price on Tuesday, the reduction is worth $12.55 billion. Reuters could