Houghton Mifflin has reached an agreement to acquire Sunburst Communications for $33.5 million. Based in Pleasantville, N.Y., Sunburst is a developer of software and video instructional materials for the school market. The company's inventory includes more than 150 software titles and 250 videocassettes.

Sunburst will come under the arm of Houghton Mifflin Interactive, headed by Connall Ryan. The company's founder, Warren Schloat, will serve as a consultant for two years and Sunburst will remain in Pleasantville.

The purchase of Sunburst, combined with HMI's earlier acquisition of the Little Planet Literary series from Applied Learning Technologies, reflects HMI's expansion into the educational marketplace and away from the consumer area.