A Montgomery County fair housing advocacy agency, faced with a total loss of funding, is taking a page out of President Reagan's guidebook on how to lose federal money and still survive.

The Community Housing Resources Board, told earlier this month that it would lose its $58,000 in federal Community Development Block Grant money in July, decided to try a little of Reagan's "public-private partnership." Through letters and meetings the board is taking its case into corporate board rooms.

The five-year-old organization is telling business leaders that without their help in raising $60,000, the housing board will die a fiscal death.

Among the functions that would die with it: a recently enacted liaison service that brings large employers together with housing specialists to find ways to provide affordable housing in the county, an information center, a bimonthly housing newsletter and a lobbying and speaker's bureau.

The Department of Housing and Urban Development would have to find another agency to take over the board's original function: to monitor the voluntary agreement between HUD and the National Association of Realtors to actively enforce federal fair housing laws.

The board was one of three private nonprofit agencies in the county told by County Executive Charles W. Gilchrist they would not be funded beginning in July because of a nearly $1 million reduction in block grant funds.

HUD officials informed the county earlier this month that it should expect a 16 to 22 percent cutback from this year's level of $4.89 million in block grant money. The block grant program, started by Congress eight years ago, provides about $4 billion yearly for urban renewal projects, both physical and social, in low- and moderate-income targeted areas. More than 90 percent of the block grant money in the county is used for physical rehabilitation.

As a consequence of the federal cutback, said county planner Kathleen Kennedy, only 15 of the 26 groups that have applied will receive block grant funds in the fiscal year starting July 1.

The Community Housing Resources Board will not be one of them if the County Council approves the Housing and Community Development Department's budget. According to contract monitor Elise Hall, the county office did not recommend the program for funding after deciding that the group should begin raising its own money and that some of its functions could be absorbed by other housing organizations in the county, such as the voluntary Suburban Maryland Fair Housing organization.

"The county certainly does not want to be in a position of not supporting fair housing," said Hall, "but if we can take care of it some other way, then it seems that other programs should be a priority."

But the director of the housing board, Arlene Simmons, argues that the agency is the only full-time fair housing lobby in the county and that no other group provides the educational or liaison services that it does.

The other two nonprofit private agencies that have been told they will not be refunded next year are the Sandy Spring Drug and Alcohol Abuse program and the National Association for the Deaf for a building renovation project.

In addition to the nonprofit private agencies that were cut from the list, Kennedy said, a number of county government projects funded this year through the program will not receive block grant money beginning in July. The county's recreation department received nearly $100,000 this year for three programs, but a similar request was denied for next year.