Barnes & Noble.com, New York, plans to purchase Fatbrain.com Inc. in a deal valued at about $64 million. Fatbrain, the third-largest online bookseller, is a business-to-business marketer specializing in professional and technical titles. Fatbrain president and CEO Dennis Capovilla and executive vice president of product development Kim Orumchian are expected to continue in their positions. The company reportedly will remain headquartered in Santa Clara, CA.