Macy’s said an employee hid as much as $154 million in delivery expenses over a three-year period, prompting the retailer to delay the release of third quarter earnings.

The New York-based department store chain – which also owns Bloomingdale’s and Bluemercury – said in a news release Monday that a single employee was behind the false accounting entries, which date to the fourth quarter of 2021. The employee no longer works at the company.

Macy’s estimates the employee hid $132 million to $154 million during a period when it had accrued approximately $4.36 billion in total delivery expenses. The company said there is no indication that it impacted its cash management or vendor payments.

The retailer released preliminary financial results Monday showing that while net sales for Bloomingdale’s and Bluemercury rose 1.4 percent and 3.2 percent, respectively, over last year, Macy’s dragged down the company’s overall net sales by 2.4 percent, to $4.74 billion. Macy’s had been scheduled to release third quarter results Tuesday, but said the report would be pushed to Dec. 11 to allow it to complete its independent investigation.

The retailer’s stock price was down more than 3 percent in late morning trading.

Chief executive Tony Spring said in the news release that company values a “culture of ethical conduct.”

“While we work diligently to complete the investigation as soon as practicable and ensure this matter is handled appropriately, our colleagues across the company are focused on serving our customers and executing our strategy for a successful holiday season,” he said.

The development comes as the industry kicks off the biggest week of the crucial holiday shopping season. The National Retail Federation projects Americans will spend $979.5 billion to $989 billion in November and December, a 2.5 to 3.5 percent increase over last year.