President Carter yesterday nominated as director of the FBI a federal judge, William H. Webster of St. Louis, whose opinions reflect an expansive view of civil rights law but little symphathy for cirminal defendants who claim they were victims of police misconduct.

Webster, 53, a Republican, was chosen personally by Carter after Attorney General Griffin B. Bell had narrowed the field to two candidates.

In a press conference in St. Louis yesterday, Webster said he hoped to make the FBI a model law enforcement agency "in terms of professionalism and awareness of constitutional procedures."

He said the FBI agents he has known are "men of character, intellect - and great dedication." But the judge sidestepped when reporters asked him to characterize the late Edgar Hoover, the bureaus first director.

Webster's nomination must be approved by the Senate. He is the second person chosen by Carter to succeed retiring FBI Director Clarence M. Kelley. The President's first choice, U.S. District Judge Frank M. Johnson Jr. of Alabama, withdrew because of ill health before his nomination came before the Senate.

Announcing the new choice yesterday. Bell said he had winnowed an initial list of 17 candidates down to two: Webster and Federal Judge J. McGarr of Chicago. Bell said he would have been equally pleased with either man.

A native of St. Louis, Webster is a graduate of Amherst College (where he was a friend and briefly, a classmate of Central Intelligence Agency Director Stanfied Turner) and Washington University Law School. He was associated with a large St. Louis law firm for 20 years, except for two years as U.S. attorney in St. Louis, before becoming a judge.

Webster was appointed to the U.S. District Court by President Nixon in 1970, and promoted in 1973 to the 8th U.S. Circuit Court of Appeals - the federal appelalte court serving seven Midwestern states.

If confirmed, Webster will take over an agency that has been rocked by charges of officials lawlessness within its ranks and by complaints by minority groups that it is insensitive to their problems.

A computer-assisted review of Webster's judicial opinions shows that he has generally been favorable toward minority plaintiffs in civil rights cases - at least to the extent of giving them a day in court.

In several opinions Webster has reversed lower-court orders dismissing civil rights complaints. The opinions show that he has been move willing potential civil rights violation in a contested and complicated body of evidence.

In a decision last spring, Webster reinstated a suit brought by a black woman who charged race and sex discrimination when she was fired by the Phillsbury Corp.

The trial court judge had ruled in Phillsbury's favor after the company presented evidence of habitual tardiness, unsatisfactory work and insubordination as grounds for firing the woman.

But Webster, writing for a 2-to-1 majority of the appellate court, said the woman should be allowed a full trial on her charges that she was given no job title or description and was paid less than white males in similar positions at the firm.

In another case, Webster faced the appeal of a man whose civil rights suit was dismissed because his lawyer failed to appear on the date set for trial. Although strict adherence to court rules would permit such a dismissal, Webster said, they should not be applied in this case, because they would penalize the plaintiff for his attorney's negligence.

Some judges' opinions are full of sweeping assertions about the philosophy of law. Other judges stick to detailed, factual discussions of the case at hand.

Webster generally falls in the latter category; his opinions are made up of concise of precedents followed by more brief statements and more citations.

But the judge broke that pattern last year in a concurring opinion on a civil liberties case that evoked considerable controversy in his home state.

The University of Missouri refused to provide a meeting place for the campus homosexual rights organization, arguing that to provide a room for the group would be to encourage sexual activities that are outlawed in that state. A federal trial court upheld the university.

But Webster's court reversed. In his concurring opinion, the judge scoffed at the university's fears.

"I have no doubt that the ancient hall of higher learning . . . will survive even the most offensive verbal assaults upon traditional moral values," Webster wrote. "Solutions to tough problems are not found in repression of ideas."

Despite what might be called a "liberal" stance in the civil liberties area, Webster has seemed to side with the prosecution in almost all the decisions he has written on criminal law.

His opinions generally give short shrift to defendants' claims that they were guilty of abusive police tactics or unconstitutional searches. In cases where he concedes that the police were wrong, Webster readily holds that the police conduct was "harmless error" - that is, not serious enough to warrant reversal of a conviction.

In a 1976 case, Webster dealt with the Fourth Amendment's command that a search warrant must describe "particularly" items to be seized.

In that case, the warrant described a "blue box" - an electronic device used to make free long distance calls - attached to a telephone and having "approximately 13 buttons or switches." The police entered the defendant's home and found no "blue box". But they siezed some tape cassettes that could be used for the same purpose as a "blue box."

Webster, writing for a unanimous appellate panel, said the cassettes could be seized and used as evidence although the warrant made no mention of records or cassettes.

Another 1976 case involved a defendant whose car was stopped and searched by narcotics agents.

The agents said they stopped the car because its taillights were mulfunctioning Webster agreed with the defendant that claim was a false "pretext" for stopping the car, and noted that "pretext" searches are generally held invalid.

But Webster, writing for a three-judge panel uphold the search in the 1976 case because the agents testified that they had seen a box containing small foil envelopes drop from the car after they stopped it. The dropped box gave police authority to search the entire car without a warrant, Webster ruled.

In a 1977 case, Webster was on a panel that had to rule on the FBI's actions in seizing and viewing, without a warrant, two allegedly obscene films.

A majority of the panel reversed the conviction of the man who sold the films, arguing that the FBI agents were required to obtain a search warrant before they looked at the movies.

Webster dissented, saying the warrantless search was legal because a private party had initially told the FBI that the titles of the movies were "Flaming Youth" and "Sex is my Bay." Webster said that information provided sufficient evidence of a crime to make a warrant unnecessary.

In announcing Webster's appointment yesterday, Bell seemed unfazed by the news that Webster has belonged to a private club in St. Louis that has been labeled "racist" by civil rights groups.

Bell, who was forced to resign from private clubs in Attorney General, responded sarcastically to questions about Webster's club membership.

"I did not know the private club rule had reached the north," the Attorney General said. "I know it has beenapplied heavily against people from Georgia."