During his first 19 months in office, President Reagan has substantially reduced the proportion of women and blacks being appointed to federal judgeships.

All but four of the 72 judges Reagan has appointed to federal trial and appellate courts by mid-August are white men. Three women have been appointed federal trial court judges and one black federal judge has been elevated to a circuit court of appeals.

This record contrasts with that of his predecessor, President Carter, whose 260 appointments to federal judgeships included 41 women and 37 blacks. During the 1980 campaign against Carter, Reagan promised, "I will also seek out women to appoint to other federal courts in an effort to bring about a better balance on the federal bench."

A review of their backgrounds shows the Reagan appointees to be predominantly graduates of prestigious law schools with successful careers in law firms or academia. Even critics of the pattern of Reagan appointees say his nominees are competent and qualified, although generally conservative in legal and political outlook.

Deputy Attorney General Edward C. Schmults said the administration looks at merit rather than race or sex in selecting judges, but has searched for qualified women and minority lawyers. "We certainly intend to do better and appoint more women and minorities," Schmults said. "It means we're going to have to work harder."

Federal judges, who are paid $70,300, to $74,300 annually, historically have been mostly patronage appointees, often suggested by the senior senator of the president's party in the state where the court vacancy is located.

But the Reagan administration has been searching for its own candidates for appellate courts, in addition to considering recommendations from U.S. senators, according to Associate Deputy Attorney General Bruce E. Fein. He said the administration continues to give great weight to senators' suggestions for federal trial court judges, and Schmults said Republican senators would be asked to find more women and black candidates.

"We choose our appointments based on one quality: their credentials and their capacity to administer even-handed justice with the philosophy of the attorney general and the president," Fein said.

Two of the most prominent nominees, Richard A. Posner and Robert H. Bork, tell something of what the administration is looking for in appellate judges.

Posner, 43, formerly a professor of law at the University of Chicago, is by all accounts brilliant; according to critics, dangerously brilliant and lacking in social conscience. After graduating first in his class at Harvard Law School, he clerked for Supreme Court Justice William J. Brennan Jr. and after a few years embarked on an academic career. A Republican, he has written 11 books and pioneered economic analysis of the law, which has emerged as a new area of jurisprudence.

Posner argues in his books that economic analysis can be used to explain areas of the law not directly related to financial questions and that economic thinking underlies most judicial opinions. Posner contends that while judges have been guided, consciously or otherwise, by the notion that one usually renders "justice" by maximizing wealth and economic efficiency, most legislators have not. As a result, he has written, many regulations, such as those providing for a minimum wage and for health and safety in the workplace, are counterproductive.

Bork, 55, was a professor of law at Yale who was named solicitor general by President Nixon. He fired Watergate Special Prosecutor Archibald Cox in 1973 on Nixon's orders in the famous "Saturday night massacre."

When the Carter administration took office, Bork returned to Yale where he was professor of law. In 1981 he joined the Washington firm of Kirkland & Ellis.

Reagan nominated Posner to be a judge on the 7th U.S. Circuit Court of Appeals and Bork to the U.S. Court of Appeals for the District of Columbia. Both were confirmed by the Senate.

While critics have complained that the Reagan administration has failed to consult organizations representing women and minorities, as Carter did, some anti-abortion activists are upset because they have not been consulted.

"In terms of the judicial appointments, it has been almost a complete washout," said Dr. Jack C. Willke, president of the National Right to Life Committee. "We have not had any impact prior to appointments, and we hear that the questions apparently are not even being asked. This has been a total disappointment to us."

The women selected for federal trial court positions are Cynthia Holcomb Hall, 53, a U.S. tax court judge chosen for the central district court in California; Elizabeth A. Kovachevich, 45, a state judge in Florida chosen for the middle district court there, and Carol Los Mansmann, 40, a Duquesne University law professor chosen for the western district of Pennsylvania.

The only black selected so far is Lawrence W. Pierce, 57, a U.S. district judge from the southern district of New York who was elevated to the 2nd U.S. Circuit Court of Appeals.

As of last month, the administration had 27 federal judicial vacancies to fill, 22 in trial courts and five at the appellate level.