Apple Inc.'s ability to pay a special dividend, viewed by investors as unlikely, is limited because almost 70 percent of its cash is outside the U.S.

While dozens of companies are paying special one-time dividends ahead of a potential jump in taxes, Apple probably won't join in partly because so much of its $121.3 billion in cash is held overseas, according to analysts. Apple is likely to focus on boosting its quarterly $2.65-a-share dividend, said Brian White of Topeka Capital Markets Inc.

Oracle Corp., Wal-Mart Stores Inc., Costco Wholesale Corp. and at least three dozen other companies have announced special dividends this quarter, according to data compiled by Bloomberg. The payouts come ahead of a potential rise in the top federal tax rate on dividends to 43.4 percent from 15 percent next year as part of the so-called fiscal cliff, a blend of tax increases and spending cuts that will take effect if U.S. lawmakers don't forge a budget deal.