A spokesman for landlords in the District said the D.C. Council's surprise move this week to approve 2 to 10 per cent rent increases was "long overdue." The amendment to an earlier emergency measure applies to most of the city's 180,000 rental apartments as of Jan. 1.

John T. O'Neill, executive vice president of the Apartment and Office Building Owners Association, said that the D.C. Rent Commission had recommended similar increases a year ago. He said the increases would have been less burdensome if increases of 5 per cent annually had been approved earlier. He said that only owner "hardship" increases had been approved during 1976 and 1977.

The rent increases were authorized by a 7-to-6 vote on an amendment to an emergency measure designed to extend the city's controversial rent control system for 90 days. A week earlier the Council had taken emergency action that appeared likely to delay any over-all rent increases.

Sheila Boykin, an organizer for the Emergency Committee to Save Rent Control, charged that the Council had used a "back-door" maneuver that would lead to excessive rent increases.

O'Neill countered that those rent increases allowed in recent years have failed to keep pace with the rate of inflation and increasing costs of taxes, services and utilities. He said the Council has not yet acted on a two-to-three-year program of rent increases that would culminate with abolition of rent controls.

One of the results of rent control in the District has been the increasing number of apartments that are sold to developers for conversion to condominium ownership. Permission has been granted to owners of buildings with a total of 1,300 units for such conversions. Other owners have converted their buildings to apartment hotels, where higher rents can be charged for short-term occupancy.