The D.C. Court of Appeals yesterday upheld the convictions on murder, assault and robbery charges of three Philadelphia Black Muslims in connection with the slaying of seven Hanafi Muslims at their headquarters on 16th Street NW almost six years ago.

In a 101-page, unsigned opinion, the appeals court carefully reviewed a number of issues raised by the defendants, including denial of a fair trial, ineffective assistance of counsel and improper pretrial procedures by the government. Each contention was rejected as meritless or as insufficient grounds to warrant reversal of the convictions.

The 1974 convictions of William Crhistian, Theodore Moody and John W. Clark followed a three-month jury trial in the D.C. Superior Court during which the government presented testimony from more than 100 witnesses.

The government contended that the slayings were carried out by the Black Muslims in retaliation for letters written by Hanafi leader Hamaas Abdul Khaalis that were critical of the Black Muslim leader, Elijah Muhammad. The victims, including five children, were members of Khaalis' family.

Four years later, March 1977, 12 Hanafi Muslims, including Khaalis, took 149 persons hostage in three downtown Washington buildings and demanded, among other things, that the men convicted of the murders be turned over to Khaalis for punishment. A young radio reporter was killed during the seige and more than 40 people were injured, including Council member Marion Berry.

Of the seven men indicated for the Jan. 18, 1973 massacre at the Hanafi house, two were acquitted of the charges, one died and a fourth, James Price, was murdered in 1975 in a Philadelphia prison.

On appeal, the three convicted men argued that the government used Price, who offered his cooperation, to infiltrate the "defense camp" and thus denied them their right to a fair trial and effective assistance of counsel. But, the appeals court said Price's coopertion was well known and noted that eventually Price refused to testify for the government.

The appeals court also held that the Superior Court had the authority to order Clark and Moody to Washington for lineups. The court dismissed Clark's claims that the prosecutors misused lineup procedures to secure his identification from a key witness and abused grand jury powers to obtain fingerprint and handwriting samples.

The case was heard in the appeals court by Associate Judges Catherine B. Kelly, George R. Gallagher and J. Walter Yeagley. The trial judge was Leonard Braman.