Amazon.com Inc. is planning to open hundreds of brick-and-mortar bookstores, the head of a major U.S. mall operator said.

Such an expansion, which Amazon itself has not confirmed, would position the world's No. 1 online retailer as a competitor to booksellers such as Barnes & Noble Inc. At present, Amazon operates a single bookstore in its home city, Seattle.

"You've got Amazon opening brick-and-mortar bookstores and their goal is to open, as I understand, 300 to 400 bookstores," Sandeep Mathrani, chief executive of General Growth Properties Inc., said on Tuesday.

He was responding to question about mall traffic during a conference call with analysts, a day after the No.2 U.S. mall operator reported quarterly earnings.

Amazon spokeswoman Sarah Gelman declined to comment.

Amazon recently opened its first bookstore in Seattle's University Village, where visitors can also test-drive Amazon's Kindle, Fire TV and other devices. In-store and online book prices would be the same, Amazon said in November.

Barnes & Noble, the largest U.S. bookstore chain, operated 640 bookstores across all 50 states as of Jan. 1.

The Wall Street Journal first reported Mathrani's comments earlier in the day.

Kevin Berry, vice president of investor relations at General Growth Properties, declined to comment beyond what was said during the conference call.