A proposal by a Northern Virginia legislator to provide real estate tax relief for owners of single family homes was attacked here yesterday by realtors and a state agency that recruits industry for the state.

At a hearing before a commission studying property tax relief proposals, business interest spokesmen said the homeowner relief measure sponsored by State Sen. Wiley F. Mitchell (R-Alexandria) would unfairly shift the tax burden to manufacturers and to owners of office buildings and appartments who would pass on higher taxes to tenants.

It was called "self-defeating counterproductive and discriminatory" by James S. Watkinson, speaking for the Virginia Association of Realtors.

Edwin E. Holm, director of research for the Virginia Division of Industrial Development, said, "In our view it would be extremely detrimental to Virginia's industrial development efforts . . . "

Mitchell's proposal, which narrowly passed the state Senate this year, would permit cities and counties to tax commercial property at a rate up to 10 percent higher than the levy on owner-occupied homes, including condominiums.

He said it is intended to redress imbalances that have resulted from the application of different assessment techniques to homes and commercially properties. He said assessments on single-family homes have been rising at an annual rate of about 10 percent in Alexandria compared with annual increases of 3 to 5 percent for commercial property.

The Mitchell bill is one of many proposals being considered by the state Revenue Resources and Economic Commission in a property tax study that was proposed by Gov. John N. Dalton and required by the General Assembly earlier this year.

The commission began its search for tax relief with a hearing on the Mitchell bill and an examination of staff-prepared data showing the effect of adopting California's Proposition 13 in Virginia.

The commission was told that imposition of California's 1 percent ceiling on property tax rates would provide significant tax reductions for almost all Northern Virginia property owners and some reductions in areas that contain 45 percent of the state's population.

In 1976, the last year for which data is complete, 22 cities and countries imposed tax rates higher than 1 percent of the fair market value of the property being taxed. A 1 percent ceiling would have cut tax bills in those cities and counties by 27 percent and forced local governments to cut services or make up for the lost revenue from other taxes.

Every city and county in Northern Virginia except Loudoun County exceeded a 1 percent tax rate in 1976. Imposition of a 1 percent ceiling would have reduced property taxes by 32 percent in Alexandria, 31 percent in Fairfax County, 26 percent in Arlington and 21 percent in Prince William County.

Mitchell told the commission that his bill is an effort "to do something about inequities in the property tax structure now before pressures for change build to the point that we have something like Proposition 13 in Virginia."