D.C. City Council member Carol Schwartz, who had been uncommitted in the rent control battle before the council, said yesterday that she favors a proposal to extend the current law, a position that could give the council the majority it needs to pass the measure.

Meanwhile, a grassroots tenant group announced that it plans to recommend that the council not only extend but strengthen the city's rent control law by limiting a landlord's ability to raise rents and streamlining the law's administration.

Today the council will open three days of public hearings on two divergent rent control bills that the council must consider before April 30, when the city's current rent control law expires.

One bill, introduced by Council Chairman David A. Clarke, would extend the provisions in the current law and the other, introduced by council member John Ray (D-At Large), would extend rent control but lift all controls on housing units as they become vacant.

Schwartz (R-At Large) said she likes neither bill, but if no alternatives are presented, she would "probably" vote for the Clarke bill because she is against Ray's vacancy decontrol provision.

"Vacancy decontrol could lead to harassment of tenants," Schwartz said. "Once you have it rent control , it is very difficult to do away with it."

The council needs seven votes to adopt legislation and, until now, the Clarke bill had the support of six members. Two members support the Ray bill. Schwartz had been one of five members who had not taken a position publicly.

Clarke said he was pleased with Schwartz' comment; "I feel more at ease now about getting the seven votes necessary to defeat vacancy decontrol."

Representatives for the Emergency Committee to Save Rental Housing, a tenant advocacy group, said yesterday at a news conference that it supports Clarke's bill, but wants some changes.

The emergency committee proposed eliminating a provision in the Clarke bill that would allow 10 percent rent increases on vacant units and limit landlords to a minimum 8 percent return on investment instead of the 10 percent minimum in the Clarke Bill and the 12 percent in the Ray bill after the landlords have filed so-called hardship petitions.

The group also called for a rent subsidy program and a change from 1973 to 1980 as the year on which rent increases are computed. The change would ease administration for the city, landlords and tenants.

"Tenants want to be sure their City Council members do not sell them out to landlords who want to exploit the short supply and the high demand for rental housing," said Jim Henderson, a committee member.