LOS ANGELES, NOV. 3 -- After hours of contentious and tense challenges by attorneys from both sides, a predominately African American jury of eight women and four men today was selected to sit in judgment of former football star O.J. Simpson.

The individuals, culled from a pool that once included more than 300 people, seemed stunned when Superior Court Judge Lance A. Ito told them that they had "survived" what at times appeared to be a human chess game played by the competing attorneys. After Ito quickly swore them in, one juror, a Hispanic 38-year-old letter carrier, covered her face and then blinked her eyes rapidly as if in shock.

Simpson, 47, faces first-degree murder charges in the June 12 slashing deaths of his ex-wife, Nicole Brown Simpson, and her friend, Ronald L. Goldman. The celebrity case has generated intense news coverage, which Ito said he feared could hurt the chances for a fair jury selection.

Today Ito congratulated the 12 people who, in his words, would be entering the "league of judges." "I want you to conduct yourself as such," he said, admonishing them to continue, at least until next week, to avoid all television, radio, books or magazines in order to serve on the jury.

"I know you can rise to the occasion despite the unusual circumstances. I know you will do what is right, and I trust you," Ito said, clasping his hand to his chest and looking intently at those waiting in the jury box.

Jury selection was a painstaking three-week process because of the racial complexity of the case. Simpson is black; the victims were white. Of the jurors selected today, eight are African American, including six women and two men. The other jurors include one Hispanic man, one Hispanic woman, one white woman and one man who described himself as white and Native American.

Fifteen alternates, an unusually high number of potential substitutes because of Ito's fear that jurors will be tainted by publicity, will be chosen in the next few weeks. Seven people who were not eliminated or chosen today will be considered in the next voir dire, and the next round of question will start Tuesday.

Simpson's jurors lead lives far different from that led by the millionaire former athlete. They come from middle-class communities in Inglewood, Long Beach, Burbank, Glendale, South Central and East Los Angeles and among their ranks are a postal worker, a letter carrier, a flight attendant, an Amtrak supervisor and a dietitian.

Two hold college degrees, nine graduated from high school. One, a truck driver who delivers Pepsi, finished 11 years of public school.

Ironically, the last juror selected was a man who has worked 25 years for Hertz Corp., the rental car company that featured Simpson in its ads and made him a household name beyond his football years.

There were some curious, if not surprising, choices for the jury. One man had been arrested twice and, during questioning last week, said he had mixed feelings about the Los Angeles Police Department. Another juror's father was a police officer. And a third man had said he could not believe Simpson, a popular California native, could commit such a crime.

Attorneys for both sides knocked 10 potential jurors out of the pool, using peremptory challenges. The prosecution eliminated eight African American potential jurors and two whites from the 39 people who appeared in court today. The defense excused two African Americans, five whites, one Hispanic and two Native Americans.

Each side accused the other of racial bias, appealing to Ito to refuse certain challenges. Ito, who listened to each side explain away the accusation, did not refuse any challenge.

Within a half hour of today's court session, it was apparent that the defense team was concerned about the intent of the prosecution challenges. Attorney Johnnie L. Cochran Jr., in a sidebar discussion, argued most vigorously after the prosecution asked for its sixth challenge -- this time against a 32-year-old black woman who worked for the U.S. Postal Service.

The woman, a security agent who uses a firearm in her job and dates a sheriff's deputy, had said in earlier questioning that she knew police officers sometimes lie in their work because of experience she had had with her supervisor.

Cochran jumped up immediately when the woman, dressed with care in a formal black velvet pantsuit, gold lame shoes and three-strand pearl choker, was dismissed. He later said the defense team was fighting "every time" the prosecution challenges an African American juror.

Defense attorney Robert L. Shapiro said, outside the courtroom, that the defense was crying foul on racial grounds because the prosecution seemed to have a strategy to "exclude black females and blacks in general."

Of the 39 people who came to court today, about 61 percent or 24 were black and about 23 percent, nine people, were white. According to 1990 census, Los Angeles County's population is 56 percent white and 11 percent black.