Investors hooked on the bonds of companies such as Apple Inc.and Oracle Corp. may soon have to look for alternatives if a taxproposal from President-elect Donald Trump becomes reality.

Trump has said he'd temporarily slash the tax rate on fundsrepatriated to the U.S. by American companies to 10% from 35%,meaning cash-rich companies that according to Bank of America Corp.stash an estimated $860 billion to $1 trillion abroad may no longerneed to turn to the bond market as a cheaper alternative to financeshare repurchases.

The impact would be substantial. Apple has become the biggestnonfinancial corporate-bond issuer in the world as it raised morethan $80 billion in just four years to finance share buybacksinstead of repatriating the more than $200 billion of cash it holdsoverseas. Oracle sold $14 billion of bonds in June to partlysupport shareholders. Bank of America expects that if taxes onoverseas cash held by American companies are reduced, bond saleswill go down by $150 billion each year.