The Arlington County Board, in a show of bipartisanship, yesterday named Larry J. Brown, a 42-year-old county executive in Minnesota, as county manager a year after Republican board members made the controversial decision to fire former county manager W. Vernon Ford.

As executive director in Ramsey County, which serves the municipality of St. Paul, Brown managed a county government with 2,880 employes, more than Arlington's estimated 2,300 workers, and with a budget of about equal size. He will assume the post Sept. 7 with a $63,000 annual salary.

"I'm really honored to be selected Arlington county manager," Brown said in a news conference. "I see this as an opportunity to help the county board and the communities of Arlington to set policies."

"We find him an articulate, energetic and powerful administrator," said County Board Chairman Stephen H. Detwiler in a prepared statement. Detwiler said he was impressed with Brown's "strong leadership" and extensive professional experience in county government, an assessment shared by other Democratic and Republican board members. The board selection of Brown was unanimous.

In Ramsey County, Brown had implemented budget cuts over the last three years, in response to federal and state budget cuts, in one of the nation's most fiscally pressed states, freezing hiring and capital spending and making cuts in social services. "Reallocating resources is all what I've been about in the last three years," Ramsey said. He said that in Ramsey County it took "a hard-nosed person to put the policies up to the board."

Brown said Arlington was likely to face more federal and state budget cuts in the future. He also said important county issues will include economic development and neighborhood preservation. But his first job is to "get to know staff," Brown said.

Brown said he supports cost-of-living increases for county personnel. "I'd like to see something tied to an area standard, whatever that is," he said.

Brown served as county executive secretary in Loudoun County from 1969 to 1971 and later as chief county administrator in counties in North Carolina and Wisconsin and as a Wisconsin state administrator involved in a variety of duties in the Community Development Department.

The board's Republican majority--Detwiler, Walter L. Frankland and Dorothy T. Grotos--voted last fall to dismiss Ford. Democratic board members attacked the firing, saying GOP board members had taken the action without public hearings or debate.

To replace Ford, the board hired Pequod Associates, a Boston consulting firm that did a nationwide search for candidates.