Houghton Mifflin Harcourt Publishers Inc. has reached a deal with more than 70 percent of its creditors to cut $3.1 billion in debt as it faces a lagging textbook market due to drops in educational funding, Reuters reported yesterday. The publisher said that it plans to restructure through a pre-packaged chapter 11 bankruptcy, a process that it said will have no impact on its day to day operations. Houghton Mifflin said that the restructuring is likely to be completed by the end of June 2012. The Boston-based publisher said a majority of its senior secured lenders and bondholders agreed to the plan to convert outstanding long-term debt to equity and create a capital structure to support its business objectives.