Robert M. Rosenthal, an automobile dealer who joined his father in an Arlington, Va., Chevrolet dealership in 1954 and over the next 60 years built the business into a $1-billion-a-year operation, died May 26 at his home in Washington. He was 91.

The cause was congestive heart failure, said a daughter, Jane Cafritz.

Mr. Rosenthal retired two years ago as president and chairman of Rosenthal Automotive, consisting of 14 auto dealerships in the metropolitan area. Over the years, the dealerships have sold vehicles manufactured by BMW, Porsche, Land Rover, Jaguar, Acura, Hyundai, Fiat, Chrysler, Volvo, Mazda, Dodge, Datsun and Pontiac. Nicholas Cafritz, Mr. Rosenthal’s grandson, said the gross income of the Rosenthal operations is $1 billion.

Robert Michael Rosenthal was born in Washington on Jan. 6, 1928. His father, Harry, had been working since 1919 as a salesman for General Motors’ Chevrolet division.

In 1954, the father and son opened a Chevrolet dealership in Arlington. By the late 1950s, Robert Rosenthal had become the president of the business, expanding it to include more than a dozen dealerships and opening its sales inventory to include Japanese and European automobiles. Harry Rosenthal died in 1986.

Robert Rosenthal is survived by his wife of 67 years, Marion Goodlevege Rosenthal of Washington; three daughters, Brooke Peterson of Sun Valley, Idaho, Jane Cafritz of Washington and Nancy Rosenthal of New York City; and three grandchildren.

Automobile dealer Robert M. Rosenthal helped build an Arlington, Va., Chevrolet dealership into a billion-dollar-a-year enterprise. (Copyright Mary Noble Ours)

To Mr. Rosenthal, automobiles were not only a vocation, but also an avocation. He collected and restored antique cars and had a special fondness for station wagons of the 1940s and 1950s featuring wood or wood-like paneling on their bodies.