She changed jobs three times, she said, when she found that men doing the same work were being paid more than she was. She also discovered when job hunting that when the New York Society of Security Analysts sent out her résumé under the name Muriel Siebert, she received no inquiries, but when the society distributed it under the name M.F. Siebert, the results were quite different.

When she decided to strike out on her own and purchase a seat on the New York Stock Exchange, she was turned down by the first nine men she asked to sponsor her application before a 10th agreed.

The exchange told her that if she was admitted, her seat would cost $445,000. It also insisted that she get a bank to lend her $300,000 of the total price, something it had never asked of an applicant before. The banks, in turn, refused to lend her the money unless the exchange admitted her. “There would be no loan until I was accepted, and I couldn’t be accepted without the loan,” she said.

After nearly two years she got the loan, from Chase Manhattan, and she was elected to the New York Stock Exchange on Dec. 28, 1967, the first woman ever to be so chosen. It proved to be a historic day but one that was not soon repeated. “For 10 years,” Ms. Siebert said, “it was 1,365 men and me.”

She continued to encounter resistance, and not only because she was a woman. Anti-Semitism proved to be a not-uncommon obstacle in the trust departments she dealt with, she said.

In 1969 she founded Muriel Siebert & Company, becoming the first woman to own and operate a brokerage firm that was a member of the New York Stock Exchange. On May 1, 1975, after the federal government did away with fixed commissions for brokers, Ms. Siebert declared her company a discount brokerage firm.

Two years later she put her company in a blind trust and accepted Governor Carey’s appointment as state superintendent of banking. Her five-year term was controversial, as she took the lead in engineering mergers and acquisitions. But in the end she liked to say that no New York bank failed during her tenure.