Словари говорят, что:

Interest expenses = затраты на выплату процентов
net of interest income = за вычетом дохода в виде процентов

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Note added at 2002-04-09 13:09:06 (GMT)
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Надеюсь, нижеприведенные цитаты помогут разобраться:
1) Net Interest Expense
Net interest expense is the amount by which a bank or corporation\'s total interest expense exceeds its total interest income.
Example:
Corporation A has total interest expense of $110 and total interest income of $10. Its net interest expense is $100 ($110 - $10).

2)Interest expense, net of interest income, was $7.3 million, $1.7 million and $4.5 million in fiscal 2000, 1999 and 1998, respectively. Interest income was $13.1 million in fiscal 2000 versus $20.5 million and $21.6 million in fiscal 1999 and 1998, respectively. The increase in net interest expense for fiscal 2000 is due to the reduction in interest income. The reduction in interest income is largely the result of TJX’s stock repurchase activity in fiscal 2000, as compared to the prior year.

Таким образом, я бы сформулировал так:
Затраты на выплату процентов (за вычетом дохода, полученного в виде процентов)