Michael Bruce Grubb, 36, senior vice president of the Rochambeau Financial Corp., an investment company he helped found last year, died of cancer Tuesday at his home in Washington.

Mr. Grubb moved to Washington in 1967. He was a stockbroker, pension management and tax investment adviser for Hornblower, Weeks, Hemphill & Noyes. He remained there until about 1972. He later worked for other major stock brokerages, including the Bache Group, before founding Rochambeau.

He had been active in Democratic politics, working as an advance man and finance committee member for various campaigns waged by Hubert Humphrey, George McGovern, Edmund S. Muskie and Sen. Edward M. Kennedy (D-Mass).

Mr. Grubb was a native of Westport, Conn. He was a 1967 graduate of Cornell University, where he was cocaptain of the lacrosse team and an All-American lacrosse player. He took graduate courses in finance at the University of Virginia.

He was a member of the City Tavern Club, the University Club, and the Cornell Club of New York.

Survivors include his mother, Marion Dennis Grubb of Bethesda; a brother, W. Dennis Grubb of Washington; a sister, Marcia Ann Grubb of Chicago, and a grandmother, Carrie Grubb of Bayville, N.Y.

The family suggests that expressions of sympathy be in the form of contributions to the St. Francis Center, 1768 Church Street NW, to the Vincent T. Lombardi Home Care Program, c/o Georgetown University Hospital, or to the Mike Grubb Lacrosse Scholarship, Cornell University, Ithaca, N.Y.