Frederic A. Arnstein, former president of the brokerage firm of Stix & Co., and a World War II veteran of the U.S. Army, died Thursday, Aug. 18, at the Villa Manor in St. Louis County. He was disagnosed with Alzheimer’s disease in 2003, and suffered a stroke the day before he died. He was 84 and was a longtime resident of Ladue.

Mr. Arnstein grew up in University City and graduated from Clayton High School in 1944. During the Second World War, he was drafted into the U.S. Army and served as a radio operator. He graduated from Michigan University in 1949 with a degree in economics. After graduation he went to work with his father at Stix & Co. The downtown brokerage firm was co-founded by Mr. Arnstein’s father in 1912.

When Mr. Arnstein’s father died in 1957, he became president of the firm. The company ceased operations in 1981. Later, Mr. Arnstein worked as a broker for the brokerage firm of Smith Moore & Co., from which he retired in 2003.

Mr. Arnstein donated his remains to the Washington University School of Medicine.

Surviving are his wife of 59 years, Sidonia M. Arnstein of University City; two sons, Stephen Arnstein of Ladue and Joseph Arnstein of Chicago, and five grandchildren.

The family had a private gathering last Sunday.