Republican E. Brooke Lee Jr, a 1982 dark-horse candidate for mayor of Washington, has formed a committee to explore his chances of winning a U.S. Senate seat in Maryland.

Lee, a real estate broker and the 67-year-old son of one of Montgomery County's oldest families, said he had sold the Kalorama Road mansion in Northwest Washington, where he lived with his mother ("for one million, one hundred and fifty thousand, cash. Lovely house but . . . . "). He has moved back to Chevy Chase with his second wife Debbie, and resumed his community and real estate work there.

Lee said he's considering running because "prominent Maryland leaders asked me to accept the candidacy. You know, we've been out here for ages. Louise Gore former GOP gubernatorial candidate is a very close friend. Alan Levey, the state chairman. All those national committee people, why they're all close friends." Levey, head of the state Republican Party, could not be reached.

"It's a question of, why do you have to have been a U.S. senator to be elected one? We own everything but a church and a graveyard but we don't ever want to boast about that," said Lee. "Really, what we're saying is, are we going to elect a political hack or are we going to elect somene who really knows something about building things and creating jobs?"

Lee has his eye on the seat being vacated by Republican Sen. Charles McC. Mathias Jr., who is retiring. Four Democrats are expected to run for the seat: U.S. Reps. Michael Barnes and Barbara Mikulski, Baltimore County Executive Donald Hutchinson and Gov. Harry Hughes. Barnes and Hutchinson have announced, Mikulski held a fund-raiser last night and has said an announcement is forthcoming. Hughes has said he is forming a fund-raising committee.

Lee is the son of the late Col. E. Brooke Lee, a prominent developer, and brother of former Maryland acting governor Blair Lee. His sister, the late Elizabeth Lee Scull, was chairman of the Montgomery County Council.

Most of the prominent Lees have been active in the Democratic Party, but Lee said his Republican ties will not hurt him. He is delaying his announcement, he said, because his wife, 26, is expecting their second child, Lee's eighth, in February.

"I just want to get her to the hospital before I start these speeches in Hagerstown and so forth," he said.