Salt Lake-based Huntsman Corp. plans to expand its annual maleic anhydride manufacturing capacity by 100 million pounds, the company said Tuesday in a statement.

Company officials said the increase is a response to demand for maleic anhydride, which is the building block for unsaturated polyester resins mainly used in the production of fiberglass reinforced resins for construction, automotive and marine products.

The expanded capacity, which could be on line as early as the first quarter of 2008, will increase Huntsman's U.S. production capacity by over 40 percent, to 335 million pounds, the company stated. The company is evaluating various sites for the expansion. It already has maleic anhydride manufacturing facilities in Pensacola, Fla., and owns a 50 percent interest in a joint venture in Moers, Germany.