Johns Manville is an under-performing and very cyclical building-products company.The deal still requires federal approval. After it is completed, Johns Manville will remain headquartered in Denver, but operate as a wholly owned subsidiary of Berkshire Hathaway. No layoffs are expected.

Manville had boasted revenues of $2.2 billion last year. It is the top seller in each of its product line except for fiberglass manufacturing, a top spot held by Owens Corning.The Manville Personal Injury Settlement Trust, established to pay victims of asbestos, which it once manufactured, owns about 76% of Manville's shares. In 1982, Manville had been forced into bankruptcy as a result of asbestos litigation costs.

Manville leases 161,000 sf at 17th and California streets in the heart of the CBD, making it one of the downtown's largest tenants. The company also owns a 400,000-sf building and 83 acres in Littleton, southwest of Denver.