The federal Equal Employment Opportunity Commission has found 58 women who claim that the financial news service founded by Mayor Bloomberg, Bloomberg LP, discriminated against them for taking maternity leave, a lawyer for the agency said.

The EEOC filed suit against Bloomberg LP in September on behalf of three women. Since then, the agency has been interviewing among the 478 woman who took maternity leave from the company at some point in the last six years, an EEOC attorney, Raechel Adams, said in a hearing yesterday at U.S. District Court in Manhattan.

“We now have 58 claimants and that number continues to grow,” Ms. Adams told Judge Loretta Preska.

In court papers, the agency says the company discriminated against women by cutting pay and placing them in jobs with less responsibility after the women reported that they were pregnant.

Mr. Bloomberg has said he is no longer involved in the daily operations of his company. He stepped down as chairman of the company’s board after he became a candidate for mayor, and when he was elected he relinquished his position as chief executive. He still owns 68% of the company, which is where most of his personal fortune lies.

The discrimination claimed by the EEOC is alleged to have occurred after Mr. Bloomberg became mayor. Still, three women in a private suit filed shortly after the federal agency’s complaint last year targeted Mr. Bloomberg personally, claiming that he “is responsible for the creation of the systemic, top-down culture of discrimination which exists within Bloomberg,” according to court documents.

An outside lawyer for Bloomberg LP, Anna Aguilar of Willkie Farr & Gallagher LLP, did not specifically address the allegations in court yesterday morning. She did indicate that the company has turned over, in electronic form, the equivalent of about a million pages of personnel information.

Asked yesterday at a City Hall press conference about the EEOC’s allegations against his company, Mr. Bloomberg said, “I have absolutely no idea.” He berated a reporter for asking a question off topic from the city budget, which was the subject of the press conference.

A spokeswoman for Bloomberg LP, Judith Czelusniak, said in a statement via e-mail that Bloomberg, in more than 25 years of operation, “has employed more than 12,000 people in the United States and fewer than two dozen employment lawsuits have been filed against the Company in the U.S.”

She continued: “In fact, several of the cases were dismissed by the courts because there was not evidence to support the claims, and others were abandoned by the plaintiffs.”