The doors of the Plaza Hotel will be closed for the building’s 100th anniversary, as a targeted grand reopening date of October 1 will be missed due to renovations that will last until later this fall or early next year.

Since 2005, owner Elad Properties has been renovating the storied hotel, converting most of the rooms to condominiums. The building is now open to some condominium buyers, though the hotel portion will be closed for a few more months, an Elad spokesman, Lloyd Kaplan, said.

The grand reopening was initially scheduled for October 1, and operator Fairmont Hotels had material on its Web site saying it was taking reservations for the fall. The Web site now says reservations are available starting January 1.

“You start out, over two and a half years ago, with what seems like a terrific target date,” Mr. Kaplan said.

He denied that there have been any delays in the building’s renovations, and noted that portions of the building will be open by the anniversary.

“The intention was to have some part of the development open October 1, and we do,” Mr. Kaplan said.

The $400 million project entails converting the 805-room hotel into a building with 181 condominium apartments, 152 condo-hotel pied-à-terre units, and 130 full-time hotel rooms. The hotel will mark its centennial anniversary with a light display, according to Mr. Kaplan, who said the condominium units were about 90% sold.

Crain’s New York Business first reported the pushed date for the reopening.