The boards and management of both companies have approved the acquisition and expect to complete the deal by March of next year.
Shares of Razorfish, whose glory days ended with the passing of the dot-com boom, closed Thursday at $1.88. The company's shares peaked in early 2000 at $55, adjusted for splits.
SBI plans to add about 200 of Razorfish's 230 employees to its staff, eliminating some administrative positions.
Privately held SBI, based in Salt Lake City, has scooped up a number of ailing dot-com consultancies this year. The company completed its acquisition of bankrupt Scient in October and agreed toLante in July.
SBI consults companies on business organization and technology for improving operations, including inventory control, marketing and sales.