Ellis M. Haller, 66, an assistant managing editor of the U.S. News and World Report magazine whose career in journalism spanned 42 years, died of a heart attack Tuesday in Orlando, Fla. He had suffered a mild heart attack a week earlier while attending a convention for the magazine and was undergoing hospital treatment when the fatal attack occurred.

Mr. Haller, who lived in Washington, had been with U.S. News and World Report for 25 years as an editor involved with business, industry and finance. More recently, as a columnist, he wrote on money matters.

He was born in Carthage, N.Y., and graduated from Syracuse University, where he was elected to Phi Beta Kappa. He had started his career in journalism while in college, serving as a correspondent for the Syracuse Journal-American and the Watertown Daily Times.

Mr. Haller joined the Wall Street Journal in 1937 as a reporter in New York City. He transferred to Chicago, where he was the Journal's bureau chief from 1941 to 1944. Later, he moved to Washington as the newspaper's White House and Treasury reporter. He was the Journal's Washington bureau chief from 1949 to 1952. His last position with the Journal was that of industrial editor in New York.

From 1953 to 1956, when he joined U.S. News and World Report as a business news writer, Mr. Haller lectured on business news writing and editing at Columbia University's Pultizer School of Journalism.

He was a member of Sigma Delta Chi, a professional journalism society, the White House Correspondents Association, the Cosmos Club and the National Press Club.

Survivors include his wife, Dorothy, a son, Ark, and a daughter, Elizabeth Summers, all of Washington, and a sister, Mrs. Francis Hodge of South Rutland, N.Y.

The family suggests that expressions of sympathy be in the form of contributions to the Sigma Delta Chi Foundation scholarship fund, or to the Heart Fund of the American Heart Association.