NEW YORK, United States — The value of Hudson's Bay Co.'s Saks Fifth Avenue flagship store has plummeted over the last five years, pulled down by retail woes and sliding rents in a high-profile Manhattan shopping district.

The building at 611 Fifth Ave. was recently appraised at $1.6 billion, according to a filing by the Toronto-based company, dropping almost 60 percent from about $3.7 billion five years ago.

The reasons for the decline include “the performance of the store relative to expectations in 2014, changes in market rents on New York’s Fifth Avenue, and the changes in the retail landscape,” the company said.

Last month, Hudson's Bay agreed to go private at a valuation of $1.45 billion in a deal that was put together by Chairman Richard Baker, who wants to reinvigorate the struggling retailer. But the proposal requires the approval of shareholders, and there's been debate among investors about the value of the company's real estate.

Activist investor Jonathan Litt has argued that the company is undervaluing its “exceptional assets” and last year he said that the Saks Fifth Avenue building should be sold.

Hudson’s Bay, trying to round up support for Baker’s proposal, went to great lengths on Tuesday to defend the appraised value of its properties, releasing a report that ran more than 200 pages on the Saks building alone.

CBRE, which conducted the appraisal, concluded the building was worth $1.6 billion as a flagship for Saks and that value of the property would drop if the company pursued a redevelopment project.

A representative for a special committee of the Hudson’s Bay board, the group that commissioned the appraisal, declined to comment.

Hudson’s Bay is spending about $279 million to upgrade the Saks store. That includes a revamp of its handbag department on the main floor, where an elevator equipped with LED art leads to the beauty section.

The retail world has changed since 2014, when the initial appraisal on the Saks building was issued. At the time, Baker called it the “most valuable retail building in the world.”

Since then, the rise of e-commerce has led to an upheaval in the retail industry, spurring bankruptcies and shuttering stores across the U.S. Those struggles have even extended to Fifth Avenue, where rents have plunged.

CBRE’s appraisal noted that rents on the stretch of Fifth Avenue where Saks is located have dropped 18 percent from their peak in 2015.

By Natalie Wong, Sandrine Rastello; Editors: Craig Giammona, Dan Reichl