The D.C. Court of Appeals heard arguments yesterday on whether as many as 100 persons convicted of sexual assaults in recent years should be allowed to ask for new, and possibly reduced, sentences because of a 1983 ruling affecting congressional review of the city's lawmaking authority.

Defense lawyers told the eight-member court that new sentencing hearings should be granted to offenders who were convicted after the House of Representatives in 1981 used a one-house veto provision -- later ruled unconstitutional -- to knock down a package of reformed sexual assault laws that had been passed by the D.C. City Council.

Yesterday's arguments are the remnants of a debate prompted last year when the Supreme Court ruled that one-house vetoes violate constitutional requirements that legislation be enacted only with the approval of both houses of Congress and presentment to the president.

Because of that ruling, Congress this month passed legislation to remedy what many authorities considered a defect in the city's charter, which allowed either branch of Congress to overturn city-passed criminal laws.

Pending before the courts are numerous appeals by offenders who contend that their sexual assault convictions and sentences are defective because the criminal reform package was repealed through a one-house veto. It is the only city-passed criminal legislation Congress has vetoed.

Officials in the U.S. attorney's office, who concede that the House action repealing the reform package was improper, maintain that the Supreme Court ruling should be applied only to future criminal convictions to avoid disrupting the court system.

Judges on the D.C. Superior Court, a lower-level body, have been split over the meaning of the high court's ruling.

Legislation approved earlier this month validated the House's repeal of the assault reform measure, while requiring that new laws passed by the city automatically will go into effect unless overturned by both houses of Congress and the president.

From questions and statements made by appeals judges during an unusual three-hour hearing yesterday, it appeared that the city's highest court was leaning toward accepting an interpretation that the Supreme Court ruling applies to the city's charter.

If so, the court must then decide whether to apply the ruling retroactively, or only in the future.

Defense lawyers have maintained that since repeal of the reformed sexual assault code was unlawful, defendants were improperly charged under the old law the code was meant to replace.

But assistant D.C. Public Defender James Klein yesterday said his office has backed away from a position that convictions obtained since 1981 should be overturned.

Klein said that since the old and the vetoed sexual assualt codes covered the same offenses, the court should focus on sentences handed down in the last three years, some of which would have been less severe under the reform package.

The Public Defender Service is representing Sylvester Cole, who was convicted of aiding and abetting a sexual assault on a minor. The law Cole was charged with violating provides a maximum penalty of life in prison, while the reform code set the maximum sentence at 20 years.

Klein argued that while the sentence Cole received -- six to 20 years -- was within the boundaries of the repealed statute, a judge considering the City Council's intent in reforming the sexual assualt code might give Cole a lighter sentence.

Attorneys for the city maintain that Congress has exclusive authority to fashion a means of delegating its authority over local affairs to elected city officials.