For example, a mutual fund is permitted to invest routinely in companies which earn up to a fixed percentage of their income from interest.

CENTERFORSECURITYPOLICY: Shariah��s Black Box

On balance, firms that derive less than 10% of its sales through Wal-Mart averaged 39.1% in gross margin, or the percentage of profit realized before items like fixed costs and interest expense are considered.

FORBES: The Wal-Mart Squeeze

Whereas an old-style trust pays out only investment income (dividends and interest) to "income" beneficiaries, a TRU pays them a fixed percentage of its value annually--typically 3% to 5%.

FORBES: New Cash From Old Trusts