The Clinton Foundation reported Thursday that it has received as much as $26.4 million in previously undisclosed payments from major corporations, universities, foreign sources and other groups, despite an ethics agreement in which the charity promised to annually disclose its donors.

The money was collected as fees from speeches by Bill, Hillary and Chelsea Clinton and was tallied internally as “revenue” rather than donations, which is why the funds had not been included in the foundation’s past public listings of its contributors, according to foundation officials.

The foundation said Bill, Hillary and Chelsea Clinton have delivered 97 speeches to benefit the charity since 2002.

The payments were disclosed late Thursday on the organization’s Web site, with speech payments listed in ranges rather than specific amounts. In total, the new dollars ranged between $12 million and $26.4 million.