The D.C. City Council should extend its temporary moratorium on the conversion of rental apartments into condominiums long enough to permit a new permanent regulatory law to be enacted, most witnesses at a public hearing declared last night.

The only dissents came from spokemen for organized apartment owners and the real estate and construction industries, who contended there is no condominium conversion crisis that justifies any further moratorium.

A 90-day conversion moratorium voted in May will expire Aug. 27 unless it is extended by the council which begins a month-long summer recess after its meeting tonight.

Willie J. Hardy (D-Ward 7), chairman of the council's housing committee, said she will propose a 60-day moratorium extension, which would expire late in October.

Last night's testimony was given at the District Building before a special study commission created ways to deal with condominium conversions.

Rick Eisen, a witness speaking for a special citizen task force, urged the commission to recommend that future condominium conversions be rationed annually among neighborhoods. A certain proportion of units should be price controlled and set aside for lower income families, he said.

Joe Davis, speaking for the Gray Panthers, an organization of the elderly, said the conversions are squeezing even "the so-called affluent people on upper Connecticut Avenue."

G.V. (Mike) Brenneman, a condominium developer who spoke for the Washington Board of Realtors and allied groups, denied that conversions are making a serious dent in the rental market. He deplored "the enactment of emergency legislation [by the council] in a highly charged emotional atmosphere."