Senator Elizabeth Warren disclosed a detailed list of compensation she received during 30 years of moonlighting as a legal consultant — about $1.9 million in all — as she and Mayor Pete Buttigieg continued a back-and-forth demanding transparency in the race for the Democratic presidential nomination.
Ms. Warren released the information abruptly on Sunday night, providing financial details to a list her campaign disclosed in May of more than 50 legal cases she had worked on while a full-time law professor, mostly at the University of Pennsylvania and Harvard.
Virtually all of the cases involved bankruptcy, her area of expertise.
Her disclosure came after escalating demands by Mr. Buttigieg, the mayor of South Bend, Ind., who has taken the lead in some of the presidential polls in Iowa, that she provide financial details of her legal work. Ms. Warren, of Massachusetts, had likewise challenged Mr. Buttigieg to provide details of his work with McKinsey & Company, a global management consulting company.
Mr. Buttigieg has said that the details of his work for the company, where he spent nearly three years beginning in 2007, are covered by a nondisclosure agreement.
While some of Ms. Warren’s work has been controversial — such as her decision to advocate for LTV Steel in a case challenging a requirement that it pay into a fund for coal miners — the information released on Sunday by Ms. Warren reveals that much of her most lucrative work involved relatively mundane cases that did not make headlines.
For example, she made $186,000 on work for Bergner & Co., a Midwestern department store chain that declared bankruptcy in 1991. She earned $160,000 as an expert witness for Fuller-Austin Insulation Co. in a case against its insurers in 2003.
In one of the more controversial cases Ms. Warren worked on, advising Dow Chemical in connection with breast-implant litigation involving its subsidiary Dow Corning, she earned about $20,000. In another newsworthy case, the Enron bankruptcy, she made about $77,000 advising one of the failed energy giant’s creditors, Rabobank.
The disclosure reveals that Ms. Warren also performed a considerable amount of free, or pro bono, legal work. She did not take any compensation for representing the Massachusetts environmental lawyer made famous by the book “A Civil Action” or for work in two cases for the AARP.
Her campaign said it could not find records for compensation in five cases.
An analysis of her legal work suggested that she took on some of the cases as an effort to preserve the integrity of the bankruptcy system and, in others, she was merely advocating on behalf of clients.
The disclosure came after accelerating hostilities between Ms. Warren and Mr. Buttigieg. Last month, Ms. Warren responded to needling by Mr. Buttigieg that she account for her private-sector work by saying, “There are some candidates who want to distract from the fact that they have not released the names of their clients.”
Tensions between the two candidates seemed to boil over last week, when, speaking at a party fund-raiser in Boston, Ms. Warren called on him not only to reveal his McKinsey clients but also to open up about his private fund-raising.
An adviser to Mr. Buttigieg, Lis Smith, responded on Twitter by suggesting that if Ms. Warren wanted to debate about transparency, she should release more details about her work as a lawyer.
Shane Goldmacher and Astead W. Herndon contributed reporting.