WASHINGTON (Dow Jones)--Armstrong Holdings Inc. said Wednesday it has received inquiries from parties, including the National Institute of Standards and Technology, investigating the fire and collapse of the World Trade Center.

The parties have asked for information on the types and amounts of Armstrong products that were in the World Trade Center, the company said in its 10-K filing with the Securities and Exchange Commission Wednesday.

Products the company manufactured that are believed to have been installed at the World Trade Center site, including the towers, are "ceiling tile, floor tile (some containing encapsulated asbestos fibers) and low-temperature (non- asbestos) pipe insulation," the filing said.

Armstrong said it isn't aware of any claim or litigation related to those products that were in place Sept. 11, 2001, the 10-K filing said.

Armstrong World, the main operating unit of Armstrong Holdings, filed for Chapter 11 bankruptcy protection in 2000 to manage asbestos liabilities. An Armstrong Holdings spokesman said that the investigators' inquiry into the World Trade Center collapse was routine and that the company did have products in the buildings.