Houghton Mifflin Co. News Release - January 23, 2006

Houghton Mifflin Company Announces the Sale of Promissor

BOSTON — January 23, 2006 — Houghton Mifflin Company today announced the sale of Promissor, a leading professional testing business, to Pearson.

"This transaction allows Houghton Mifflin to keenly focus our resources on growing our core educational and trade and reference publishing businesses, and on serving our customers more effectively," said Tony Lucki, president and CEO of Houghton Mifflin Company. "Promissor has made solid contributions to Houghton Mifflin. Under the new ownership, Promissor will be able to continue its tradition of providing quality assessment services."

Promissor is a leading provider of licensing examinations for state and federal regulatory bodies in the United States. It holds a wide range of contracts to assess professionals in the real estate, insurance, mortgage broking, contracting and healthcare industries. Based in Philadelphia, Chicago and London, the company owns and operates a network of 130 test centers in the United States.

About Houghton Mifflin Company
Boston-based Houghton Mifflin Company is one of the leading educational publishers in the United States, with more than $1 billion in sales. Houghton Mifflin publishes textbooks, instructional technology, assessments and other educational materials for elementary and secondary schools and colleges. The Company also publishes an extensive line of reference works and award-winning fiction and nonfiction for adults and young readers. Houghton Mifflin offers computer-administered testing programs and services for the professional and certification markets. With its origins dating back to 1832, Houghton Mifflin combines its tradition of excellence with a commitment to innovation. The Company's Web site can be found at www.hmco.com.