“A company sitting on a $150 billion cash pile planning a $17 billion bond issue to buy back its shares? It sounds like a bad joke, and Apple, the company in question, is keenly aware of it. Specifically, 88 percent of Apple’s cash, or $130 billion, is overseas, and were the company to bring it home, the taxman would claim about a third of it. Last year, when the SEC asked Apple about its foreign earnings, it replied that most of it was generated by Irish subsidiaries and ‘intended to be indefinitely reinvested in operations outside the U.S.’ If Apple issues debt in Europe, the proceeds could be used for the buyback, while the interest and principal owed to debt investors would be paid out of the Irish cash pile.”
http://www.bloombergview.com/articles/2014-04-28/why-apple-has-to-borrow-17-billion