ST. LOUIS, Mo. (KMOX) — The Millennium Hotel abruptly closed most of its rooms this past weekend. The 780 room hotel in downtown St. Louis had planned on shutting down some 600 rooms as part of a renovation expected to start this coming fall.

General Manager Dominic Smart told the St. Louis Business Journal that 400 rooms in the hotel’s south tower were taken out of use Sunday. The rest will be done in stages.

Smart said the hotel, had been planning a “comprehensive renovation” for some time, and that the project was recently “fast-tracked” by parent company Millennium & Copthorne Hotels plc, based in London.

The sudden closure of more than half of the rooms at the Millennium have left several groups without reservations. John Bettag, vice president of sales at the St. Louis Convention and Visitors Commission, said the CVC is working to provide accommodations for about a half-dozen groups.