NEW YORK (Reuters) - A Citigroup ( C/PN ) managing director said the bank failed to protect her from a supervisor's violent threats and abuse because of its "pervasive" culture of sexual harassment and gender discrimination, according to an amended legal filing on Monday.

Ardith Lindsey, who worked as Americas head of electronic sales trading, added details to her November lawsuit outlining threats from Mani Singh, once the bank's North America Markets head of cash equity execution services. He resigned in November 2022.

Lindsey said that after she ended their relationship in October 2022, Singh began five days of incessant phone calls and expletive-laden text messages, such as "I am going to set you on fire," and "Kids no kids I don't give a fuck [I] plan to burn it all down."

Lindsey said Singh subjected her to many years of increasingly volatile abuse, sometimes fueled by alcohol or drugs, including alleged threats to harm her and her family and destroy her career if she resisted his advances.

The bank "chose to overlook numerous red flags about Singh's conduct," Lindsey said. Instead, it "promoted him and, at the same time, did not protect Lindsey and many other women."

Lindsey is on leave from the bank, she said.

Citigroup ( C/PN ) was not immediately available to comment. Singh did not immediately respond to a voicemail seeking comment.

In November, Citigroup ( C/PN ) said it would defend against Lindsey's claims.

"No one should ever be discriminated against or harassed in the workplace," the third-largest U.S. bank said at the time.

It called the conduct detailed in the original filing "deplorable," but said the relationship described by Lindsey differed significantly from her earlier account.

A lawyer who has represented Singh in separate litigation did not respond to requests for comment in November.

Lindsey also alleged she was assaulted by a senior manager who forcibly kissed her months after she joined the bank at age 24 in 2007.

"Citi, especially in the equities division, has been a workplace where sexual harassment and gender discrimination are rampant and egregious," Lindsey said in the amended complaint which detailed additional allegations.

She alleged some male bankers would visit strip clubs, drink excessively, make sexualized comments about female colleagues, or use cocaine in the office.

Lindsey named several senior Citigroup ( C/PN ) executives who were allegedly involved in discrimination or sexual harassment, and cited job titles of others who were involved in sexual relationships with direct reports or junior employees.

Unnamed female employees who raised their concerns with managers and human resources faced retaliation or left the bank, Lindsey said.

She also alleged that Citigroup ( C/PN ) did not respond to her concerns until she filed the lawsuit, almost a year after she reported Singh's text messages.

When a senior manager addressed her lawsuit with colleagues, he tried to dismiss Lindsey and discredit her as causing trouble, she said.

The bank's head of markets, Andy Morton, sent a memo asking employees to speak up if they saw inappropriate behavior, Reuters reported in November. The company also sent a survey to women in the markets division asking about the workplace environment, Lindsey said.

Lindsey's doctors have diagnosed her with post-traumatic stress disorder, depression and memory loss that have rendered her unable to work, according to the complaint.

The lawsuit comes after years of Wall Street banks trying to diversify their ranks and shed their boys' club image.

Wells Fargo was accused of sex discrimination in a lawsuit earlier this month by a bond saleswoman who said the bank denied pay and promotions available to men and tolerated an "unapologetically sexist" workplace.

Last year, Goldman Sachs agreed to pay $215 million to settle a class action alleging widespread bias against women in pay and promotions, ending one of the highest-profile lawsuits claiming unequal treatment of women on Wall Street.

The case is Lindsey v Citigroup Global Markets Inc, U.S. District Court, Southern District of New York, No. 23-10166.