In a report posted on its Web site, Houghton Mifflin Harcourt said that it received a notice from stockholders of at least 25% of its stock that the company begin the process of starting an initial public offering. Under the terms of its most recent financial reorganization, HMH shareholders had the right to demand that the publisher be bought public through an IPO.

As part of the IPO, the shareholders invoked a clause that mandates that all stockholders sell 15% of HMH’s existing common stock.