Previous executives had estimated between $400 million and $600 million in savings from integrating operations with Illinois-based OfficeMax.
Smith said he plans to complete his reorganization of the company by the end of February. Office Depot notified the State of Illinois that it plans to close the OfficeMax headquarters in Naperville, Ill., and lay off 1,600 employees.
The CEO made the announcements with Office Depot's reporting of its first earnings since completing its $1.2 billion merger with OfficeMax in November.
The combined companies posted a fourth-quarter loss of $144 million, or 34 cents per share. For the year, the Boca Raton office-supply retailer's loss was $93 million, or 29 cents a share.
Prior quarter and year results are not comparable as both include the newly integrated OfficeMax's results, the company said.
Sales were $3.5 billion in the quarter ended Dec. 28 and $11.2 billion for the full year, including $939 million of sales from OfficeMax, Office Depot said.
Smith is scheduled to hold a conference call with analysts at 8 a.m. today.