SEATTLE — Amazon signs may be headed to more physical storefronts.

The Internet retailer plans to open more brick-and-mortar bookstores following the unveiling last year of one such location here in its hometown, according to a person briefed on the matter who spoke on the condition of anonymity to discuss confidential plans.

But the company’s plans for physical stores are modest, this person said, especially in comparison with reports of an expansion suggested by an unusual source, the chief of a large shopping mall operator.

Sandeep Mathrani, chief executive of the mall operator General Growth Properties, was answering questions from analysts on Tuesday about foot traffic in malls when he said, of Amazon’s bookstore plans, “Their goal is to open, as I understand, 300 to 400 bookstores,” according to a recording of the call.

Mr. Mathrani did not say how he heard about Amazon’s plans. Kevin Berry, a spokesman for General Growth Properties, declined to comment further. The Wall Street Journal earlier reported on Mr. Mathrani’s comments about Amazon.