A federal appeals court rejected a challenge yesterday by three Arlington women who claimed they were being denied food stamp benefits because Virginia officials consider their housing assistance payments as income.

The 4th U.S. Circuit Court of Appeals ruling rebuffed a suit filed two years ago by Legal Services of Northern Virginia, a legal advocacy group, which charged that the state had denied the benefits under an unfair and discriminatory regulation.

The appeals court upheld the regulation in a 10-page opinion, noting that Arlington's rent subsidy payments are "generous" but must be considered as income under the federal law that established the food stamp program. The ruling, in a case filed on behalf of the three women and nearly 1,000 households in the county, upheld a 1981 decision by District Judge Richard L. Williams of Alexandria.

The decision means that 86-year-old Mildred S. Ruhe, one of the three women, will get about $14 less in food stamps than she would have received if the court had sided with her, said Charles P. Sabatino, a Legal Services attorney.

Under federal regulations, housing assistance payments that go directly to landlords, for example, are not counted against an individual's income when food stamp benefits are determined. "It may be that if Arlington County, which is generous in its rent subsidy payments, would alter their form, the plaintiffs could receive more food stamps," the panel suggested.

The Arlington payments must be considered as income, the appeals court noted, because "there is no statutory requirement in the Arlington County program that the participant actually spend the proceeds of the subsidy on housing."