Nine months ago, Bowles, C. Ford confronted what, by most accounts, was an administrative mess when he became head of the District of Columbia's embattled rent control agency.

Landlords, seeking permission to raise their rents, and tenants, challenging allegedly excessive rent increases, faced prolonged waits before their petitions produced any action.Often these delays were much longer than permitted under the city's rent control law. Confusion was rife. For some time, the agency had appeared virtually leaderless, and criticism was mounting.

Now, Ford contends -- and a number of other officials agree -- that much has changed at the Rental Accommodations Office. Delays apparently have been reduced.New legal interpretations are said to have been codified. The agency has hired additional hearing examiners and other administrative specialists.

A recent city auditor's study concluded that the rent control agency is capable of handling its work and is likely to become increasingly efficient. Even the Apartment and Office Building Association of Metropolitan Washington, the largest local landlords' group, conceded in an otherwise critical report that the Rental Accommodations Office had shown at least temporary improvement in dealing with petitions by landlords and tenants.

"I don't anticipate ever again having the kind of situation I had when I got here," said Ford, a former Urban Mass Transportation Administration economist who took over as the city's rent control administration April 11, in an interview last month. "Those days are gone forever."

Despite signs of improvement in recent months, however, the Rental Accommodations Office continues to draw criticism, especially from landlords and their lawyers in proceedings before the agency. Many real estate specialists still point to the agency's operations as evidence that the rent control law is unworkable.

One key debate centers on what is known as the agency's backlog, the number of petitions filed by landlords and tenants on which the agency has failed to issue a decision within 90 days. This is the maximum time permitted under current, although frequently violated, regulations for the agency to act on a petition.

Accordingly to rent control officials, the backlog of landlord and tenant petitions that had been pending for more than 90 days stood at 211 cases when Ford took office last April. the peak of 311 cases had been reached in August, 1976, they said. By contrast, the agency reported a backlog of only 46 such petitions as of last Dec. 1.

Even these statistics are in dispute. "We still don't believe the administrator's statistics on the backlog," says Raymond Howar, a landlord representative on the Rental Accommodations Commission, the board that oversees the rent control agency. Howar believes the backlog is larger.

Eric A. Von Salzen, a lawyer who has frequently represented landlords in rent control proceedings, said in an interview that 6 to 10 months usually are required for completion of hearings, preliminary decisions and appeals of landlords' petitions for rent increases. "My own experience has not shown a particularly notable improvement," he said.

Even though the backlog may have been reduced, other lawyers, representing both landlords and tenants, say numerous problems still beset the agency. They complain that hearing examiners often are reversed on appeal, that correspondence may be lost or misplaced, that legal precedents may be overlooked and that petitions receive only cursory consideration in their initial stages.

Statistics compiled by the Rental Accommodations Commission show that decisions by the agency's hearing examiners are reversed on appeal by the commission more often than they are upheld.

Of 159 appeals on which the commission had ruled as of last Oct. 31, 82 resulted in reversals, according to the commission statistics. Only 52 of the hearing examiner's decisions were affirmed on appeal. The remaining appeals were dismissed or withdrawn.

City officials and lawyers who handle rent control cases attribute the large number of reversals partly to legal, accounting or other errors made by the agency's often-inexperienced hearing examiners. But they also say the reversals stem, in part, from reasonable differences in interpretation of new statute by hearing examiners and the commission.

"Our reversal rate is relatively high," Albert M. Williams Jr., Ford's deputy administrator, conceded during last month's interview in ford's office. "The (hearing) examiners are still learning. The commission is doing the same thing. The commission has reversed itself on several issues," he said.

Recently enacted legislation, designed to extend the city's rent control program until Sept. 30, 1980, also is expected to have some impact on the way the agency administers the law. The legislation, which must undergo congressional review, provides for automatic rent increases annually for most landlords and modifies other rent control procedures.

Some lawyers and city officials believe the legislation may ease the rent control agency's job, partly by reducing the number of petitions for rent increases filed by the city's landlords. Other lawyers express skepticism, noting that the new law is expected to face prolonged court challenges on several key issues.