A woman with two young children wants a two-bedroom apartment, but is told by landlords that she has to rent a three-bedroom apartment - which she cannot afford - because her children are of different sexes.

Two sisters who want to live together find apartments they like, but the landlords say each of them has to put up a full month's rent as a deposit.The women can't afford it.

Two doctors, male and female, try to find an apartment in Montgomery County, but the landlord says they have to be married before he can rent to them.

Although it has been a decade since the federal Civil Rights Act was enacted, making it illegal to discriminate in the sale or rental of housing because of race, color, religion or national origin, the above situations are typical of a continuing problem of discrimination in the local housing market, according to the human rights officials in local jurisdictions who hear such complaints.

While racial bias was once the overwhelming concern of fair housing advocates, sex or marital status is more often the basis of discrimination today, according to the complaints these government offices have received. It was not until 1974 that the federal law made discrimination based on sex illegal.

"There is an increased number of women who run into discrimination," said James Harvey, executive director of the Metropolitan Washington Planning and Housing Association, an organisation concerned with civil rights and housing.

"I think (discrimination against women) is worse than what's surfacing. A lot of women don't know what their rights are."

Harvey says that while "Washington is miles ahead of any other metropolitan area as far as open housing goes . . . that adoesn't mean we have reached a totally free and open market. Discrimination still occurs in a lot of subtle ways."

Although local laws make many types of housing bias illegal, they still do not prevent all types of discrimination, according to Carol Rende, director of the planning group's housing opportunities center.

The three examples given earlier would, however, constitute discrimination under the local laws now in force, Rende said. Requiring separate bedrooms for children solely because they are of different sexes would be discrimination on the basis of sex, she said, while the other two examples would constitute discrimination on the basis of marital status.

The most comprehensive of local laws is the District of Columbia law which is "probably one of the strongest laws in the nation," according to Rende. Like the other laws in this area, the District law prevents housing discrimination based on race, color, religion, national origin, sex, age and marital status.

The comprehensive D.C. law also covers discrimination in seven more areas - personal appearance, a person's family responsibilities, physical handicap, status as a student, political affiliation, source of income and place of business.

The human rights law in Prince George's County covers a range of areas nearly as broad as the D.C. law, including discrimination based on occupation and mental handicap. The laws in Montgomery and Fairfax counties are less comprehensive, covering little more race, color, sex, age, religion, national origin and marital status.

The number of discrimination complaints received by area human rights organizations is smaller now than in past years, officials say. In Prince George's County, for instance, the human relations commission has received about 70 complaints in the last 12 months, compared with 200 to 300 in past years, according to executive director William Welch.

"More people might complain if they knew they were being discriminated against," he said. There is "far less" racial bias now in the county's housing market than in past years, he added.

Similarly, in Fairfax County "the preponderance of housing discrimination cases are based on marital status rather than on race," according to the human rights commission's executive director, Tricia Horton.

The situation of landlords requiring divorced women to rent apartments with one bedroom for each child is a big problem in Fairfax County, Horton said. "We get a lot of those calls and there is nothing I can do about them," she said. There is no law in Fairfax County preventing landlords from making such a requirement, which she said is used to keep families headed by women out of apartment complexes.

According to Harvey, the tight local housing market adds to the continuing problems of discrimination. "The demand (for housing) outstrips the supply and this allows for more discriminatory practices to take place. The landlord is in the driver's seat," he said.

"As a result of supply and demand, discrimination is becoming a Socioeconomic thing," says H. R. Crawford, a real estate management specialist who is chairman of the local housing committee of the NAACP.

Lower-income families, both black and white, are being forced out of the tight District housing market and are moving into Prince George's County, which is becoming the Harlem of the area, while the District is the Manhattan, said Crawford, who manages apartments in the District and who is a candidate for the City Council.

According to human rights officials the movement of blacks out of the city is greater because of racial "steering " by real estate agents. They say some agents steer clients into certain neighborhoods by not showing them the houses available in other areas.

"Realtors are generally going to steer black families into Prince George's County and whites into the Virginia counties," Welch, the Prince George's human rights official, said. He said he has received a rash of complaints about steering but said they are often difficult to prove.

Horton said she has received some complaints about steering, but observes that "Fairfax has a reputation as a white community that serves to discourage minority people from even looking for housing in the county."

No such complaints have been made to the human relations commission in Montgomery County, according to deputy executive secretary Freda Mauldin.

"The price of houses in Montgomery County is so high, realtors are inclined to sell to anyone who has the money," she said.

Many people involved with the local housing market expressed concern about the lack of an adequate supply of houses for families with low and moderate incomes.

"The segment of families who can't afford housing is getting bigger," Harvey said. "It's going to take some strong government action, some resources and money, to accomodate that group that really needs housing," he said.