Macy’s reported stronger-than-expected sales for the third quarter and said it’s delaying the release of its full quarterly results after it discovered an employee intentionally hid up to $154 million of expenses over several years.

Macy’s announced Monday that a single employee was responsible for so many accounting irregularities that the company was forced to delay its quarterly earnings report, which the retailer had planned to release Tuesday.

The employee "intentionally made erroneous accounting accrual entries" to hide millions of dollars, Macy's said. The error forced the company to delay reporting its third quarter results.