Robert M. Montague, 89, a retired brigadier general in the Marine Corps and a veteran of both world wars, died Dec. 4 at the Fairfax Nursing Center in Fairfax. He had diabetes.

Gen. Montague was commissioned in the Marine Corps in 1917 when the United States entered World War I. He served in all the major campaigns in which the Marines took part in France, beginning with Chateau Thierry and going through the Argonne Forest. He earned the Silver Star Medal and three Croix de Guerre from the French government.

In the years between the wars, he served in Haita, Nicaragua, in command of Marine detachments on Navy ships, in China and in the Philippines. He also had several assignments in the United States.

During World War II, he commanded the 19th Marine Regiment in the Solomon and Treasure Island campaigns.

He retired in 1946 and made his home in Quantico, Va. For several years, he was a part-time reading teacher of small children in Fredericksburg, Va. He also was a member of the Sojourners, a former governor of District 36 of Toastmasters International and a Knight of the Golden Circle of the Army & Navy Club in Washington. He moved to the Fairfax Nursing Center about three years ago.

Gen. Montague was born in Salem, Minn., and grew up in Idaho. He earned a degree in civil engineering from the University of Idaho before beginning his military career.

Survivors include his wife, the former Marion E. Ryan, of Alexandria; two children, Marion M. and Robert M. Jr., also of Alexandria, and two brothers, James E., of Portland, Ore., and Frank B., of Goldendale, Wash.

The family suggests that expressions of sympathy be in the form of contributions to the Kidney Foundation.