New York, NY/Authorlink News/ March 15, 2011-Houghton Mifflin Harcourt CEO Barry O’Callaghan has resigned, but will remain a senior adviser to the company, according to a recent industry news report. The publisher's board has appointed CFO Michael Muldowney to serve as interim CEO.

Last year's financial results were disappointing and the company has struggled to refinance its debt. O'Callaghan told the news media that he couldn't be held responsible for things he can't control, likely referring to State budgets for text books.