Mr. Niedt joined Steelcote, a manufacturer of epoxy and other industrial maintenance coatings, more than 40 years ago, and worked mostly in sales and marketing capacities with the company. After Steelcote was sold in 1992, he remained with the company as a sales manager until he became ill in 1998.

Steelcote was started by Anthony Niedt and his brother, George, who was Greg Niedt's father. The company was a pioneer in the development of epoxy coatings and also manufactured polyurethanes. Steelcote products were sold worldwide for diverse uses, with applications ranging from ocean liners to early space satellites.

Greg Niedt was born and reared in St. Louis, and graduated from Grinnell College in Grinnell, Iowa. He served in the Navy during the Korean War, and held the rank of lieutenant. He was a member of several organizations, including the National Association of Corrosion Engineers, the Lafayette Square Restoration Committee in St. Louis, and the World Wildlife Foundation.

Mr. Niedt is survived by his wife Moira; two sons, Dr. George W. Niedt of Pelham, NY, and Mark L. Niedt of Denver; a stepdaughter; two stepsons; and four grandchildren.