A coalition of tenant groups yesterday released a memorandum written by an aide to Mayor Marion Barry that, it said, shows the mayor has "actively been working" with the city's organized landlords to scrap rent control.

The memo, written April 10 by Judith W. Rogers, then the assistant city administrator for intergovernmental relations, said several amendments to the rent-control law proposed by real estate executive Joseph Schuble "appear to be of interest to the mayor."

The memo said the mayor wanted "a further briefing with representatives of developers, real estate interests and property managers" on the proposals.

Barry, speaking at his own news conference later in the day, firmly denied he supports an end to rent control and has taken sides with the landlords. "Anyone who has an idea . . . gets the same treatment," the mayor said.

The memo was released by the Emergency Committee to Save Rental Housing during a District Building news conference called to promote legislation requiring an almost-total moratorium on further conversions of rental housing to condominiums.

Kyle Holder, spokesman for the group, asserted that the landlord-proposed legislation would hasten the condo conversion trend. He said the mayor met with the landlord group, the Apartment and Office Building Association, but refused until Wednesday to set a meeting with the Emergency Committee. It is scheduled for next Tuesday.

John T. O'Neill, executive vice president of the apartment owners' group, scoffed at any suggestion that the mayor had joined his side.

"We have not been successful in getting the City Council or the mayor-this one or the last one (Walter E. Washington)-to do more to save rental housing" by easing or ending rent control, O'Neill told a reporter.

Schuble, president of the apartment organization and executive vice president of Dreyfuss Brothers, a realty firm, said he suggested to the mayor that a general decontrol of apartment rents could be accompanied by the reservation of perhaps 25 percent of all units for low-rent occupancy by poorer tenants.