Ghislaine Maxwell, the former companion to the disgraced financier Jeffrey Epstein, was convicted on Wednesday of conspiring with him for at least a decade to recruit, groom and sexually abuse underage girls.

A federal jury in Manhattan found Ms. Maxwell, 60, the daughter of a British media mogul, guilty of sex trafficking and four of the five other charges against her. She was acquitted of one count of enticing a minor to travel across state lines to engage in an illegal sexual act.

Ms. Maxwell’s trial was widely seen as the courtroom reckoning that Mr. Epstein never had. Mr. Epstein, who was arrested in July 2019 at the age of 66, killed himself in a Manhattan jail cell the following month, the medical examiner ruled, while awaiting his own trial on sex trafficking charges. Ms. Maxwell was arrested a year later.

The verdict came late in the afternoon of the jury’s fifth full day of deliberations. After the jury sent a note saying it had reached a decision, Ms. Maxwell, wearing dark clothes and a dark-colored mask, was ushered into the courtroom and sat at the corner of the defense table. She poured water from a plastic bottle into a paper cup and took a sip.

The jurors filed into the courtroom at 5:04 p.m., and Judge Alison J. Nathan read the verdict aloud: guilty on five of the six counts. Ms. Maxwell sat still through the reading of the verdict. She then touched her face and again poured water into a cup and drank. She leaned over to speak with one of her lawyers, who patted her on the back.

After the jurors filed out of the courtroom, Ms. Maxwell stood, cast a brief glance in the direction of her siblings — two sisters and a brother who were seated in the first row of the spectator gallery — and was escorted quickly out of the courtroom, without speaking to her lawyers.

Ms. Maxwell’s conviction closed another chapter in the saga of Mr. Epstein, whose lurid exploits, dealings with the criminal justice system and cast of famous friends made him — and, by extension, Ms. Maxwell — the subject of intense public scrutiny for years.

In her trial, the government called four accusers — two used pseudonyms and one only a partial name — who testified that they had been served up to Mr. Epstein to be sexually abused. Ms. Maxwell was present for some of the abuse, according to the testimony, and played a role in enticing and grooming some of the victims.

Damian Williams, the U.S. attorney for the Southern District of New York, said in a statement Wednesday night: “The road to justice has been far too long. But, today, justice has been done. I want to commend the bravery of the girls — now grown women — who stepped out of the shadows and into the courtroom.”

One of Ms. Maxwell’s lawyers, Bobbi C. Sternheim, said outside the courthouse: “We firmly believe in Ghislaine’s innocence. Obviously, we are very disappointed with the verdict. We have already started working on the appeal and we are confident that she will be vindicated.”

Ms. Maxwell’s siblings left the courthouse in Lower Manhattan without speaking to the gathered crowds and cameras outside.

Judge Nathan did not set a date for Ms. Maxwell to be sentenced. On the most serious of the counts for which she was convicted — sex trafficking of minors — she could face up to 40 years in prison. Another count carries a potential 10-year sentence, and the three others, all conspiracy counts, carry sentences of up to five years each.

Ms. Maxwell also faces a separate trial, in the same court, on two counts of perjury, stemming from 2016 depositions she gave in a lawsuit related to Mr. Epstein.

Ms. Maxwell’s trial, once expected to last up to six weeks, moved quickly as the government pared its witness list and presented a case over 10 days that centered on the four accusers.

Two of the women testified that Mr. Epstein started engaging in sex acts with them when they were only 14 years old. One said Ms. Maxwell was sometimes present in the encounters, and the other said Ms. Maxwell had molested her directly by touching her breasts.

Two accusers depicted Ms. Maxwell, a former socialite, as a kind of mentor and big sister — a picture of elegance and sophistication, one recalled — who took them shopping and to the movies in what prosecutors said was a ploy to build trust. Then she played a key role in normalizing sexualized massages with Mr. Epstein that, in some cases, led to years of sexual abuse.

“Maxwell was a sophisticated predator who knew exactly what she was doing,” a prosecutor, Alison Moe, told the jury in closing arguments last week. “She manipulated her victims, and she groomed them for sexual abuse.”

The verdict was largely a rejection of Ms. Maxwell’s defense, which centered on an argument that the government’s case was based on flimsy evidence, prosecutors’ animus toward Mr. Epstein and the inconsistent accounts of women who were motivated by money to point the finger at Ms. Maxwell.

Throughout the trial, Ms. Maxwell’s lawyers sought to raise doubts about the testimony of her accusers, emphasize the distance between her and Mr. Epstein and criticize how the investigation was conducted.

“The government wants you to speculate, over and over,” a lawyer for Ms. Maxwell, Laura Menninger, told the jury during closing arguments. She said Ms. Maxwell was on trial because of her relationship with Mr. Epstein. “Maybe that was the biggest mistake of her life, but it was not a crime,” she said.

Mr. Epstein’s name surfaced repeatedly during Ms. Maxwell’s trial, and her lawyers spent much of their time trying to distance her from the man who was once also her boyfriend and is now seen as one of the most notorious sex offenders in modern American history.

Ms. Maxwell’s accusers included the two women who testified under pseudonyms — “Jane,” a soap opera actress, and “Kate,” a British model, actress and singer from a wealthy family. A third accuser, Carolyn, used only her first name. She described herself as a middle-school dropout who had become addicted to drugs and was sexually abused by her grandfather at the age of 4. The fourth accuser, Annie Farmer, who has a Ph.D. in educational psychology and works as an educational therapist, testified under her true name.

If the accusers seemed to have contrasting backgrounds, the accounts they gave of how they were enticed into Mr. Epstein’s world shared a common thread: Ms. Maxwell.

Jane testified how Ms. Maxwell, a “tall, thin woman” with a “cute little Yorkie,” strolled up to her, followed by Mr. Epstein, as she sat with friends at the age of 14, eating ice cream at a summer arts camp in Michigan. That chance meeting led to an invitation to Mr. Epstein’s house in Palm Beach, Fla., and what prosecutors said was years of sexual abuse.

Carolyn testified that when she was also 14, a friend of her boyfriend’s asked her if she wanted to make money by giving massages to a man who turned out to be Mr. Epstein. Ms. Maxwell met her and the friend at the door to Mr. Epstein’s Palm Beach house; Carolyn told the jury that in the years that followed, she visited the house two or three times a week to perform sexualized massages in appointments that were often arranged by Ms. Maxwell, whom she said she always saw when she entered the house through the kitchen door.

Carolyn’s experience formed the basis of the weightiest count on which Ms. Maxwell was convicted — sex trafficking of a minor. The jury had to find that Ms. Maxwell recruited Carolyn to engage in sex acts with Mr. Epstein and encouraged her to recruit other girls, and that the girls received money or gifts in exchange, as Carolyn testified.

Two other prosecution witnesses, Larry Visoski and David Rodgers, former pilots who had flown Mr. Epstein’s planes, both testified that Ms. Maxwell had unique authority among his employees. She was his “No. 2,” each man told the jury.

“This case is about Ghislaine Maxwell, the crimes she committed,” another prosecutor, Maurene Comey, said in a government rebuttal. “It’s about the children that she targeted, the steps that she took to serve those children up to be abused. It’s about her own participation in that abuse.”

Ms. Farmer, one of the accusers who testified against Ms. Maxwell, said in a statement that she was “relieved and grateful that the jury recognized the pattern of predatory behavior that Maxwell engaged in for years and found her guilty of these crimes.”

“She has caused hurt to many more women than the few of us who had the chance to testify in the courtroom,” Ms. Farmer said.

Ms. Maxwell chose not to testify, but her lawyers sought to undermine the government’s portrayal of their client, sharply cross-examining the accusers to raise questions about the reliability of their testimony, and offering witnesses who worked for Mr. Epstein and said they had not seen the kind sexual abuse that was described at the trial. The defense also presented an expert who testified about the fallibility of memory.

But Ms. Maxwell’s lawyers, who once said they would need two weeks to present her case, rested their case after only two days, after unsuccessfully arguing for more time to summon additional witnesses.

During their five days of deliberation, jurors sent notes seeking transcripts of testimony from more than a dozen witnesses, clarification on the law and office supplies. As the week wore on with no verdict in sight, and Omicron cases spread across the city, Judge Nathan raised concerns that an infection might cause a mistrial.

She told jurors on Tuesday that they might have to deliberate through Friday. On Wednesday afternoon, the jurors asked for a transcript of Mr. Visoski's testimony. Two and a half hours later, they had a verdict.