Macy's has announced a four-year plan to revamp its Herald Square flagship store in New York City.

The department store chain yesterday (1 November) said it will invest some US$400m in the project with plans including new selling space to allow for expanded assortments, and upgraded presentations in key merchandise categories including shoes, handbags, cosmetics and fashion brands.

The work will begin in spring 2012 and continue in phases until autumn 2015. The majority of every floor, virtually every department and the exterior of the building will be improved over the course of the project, the retailer said.

The store will remain open and operational through the course of the construction, with the location of some departments shifting temporarily.

Macy's will open the "world's largest women' shoe department" covering 39,000 square feet of space on the second floor.

It will also expand the men's merchandise department, which will grow to cover around 200,000 square feet of space over seven floors on the Seventh Avenue building.

"The excitement, size and scale of this remodel reinforces our conviction that Macy's Herald Square is and will remain a retail store in a class by itself," said chairman, president and CEO Terry Lundgren.

"It is our company's most productive store, and experience shows that improvements in this location consistently result in higher customer traffic and sales volume. Our upcoming top-to-bottom remodel represents an investment in the future growth of our business as New York City continues to evolve as a world capital and shopping destination."