The Nielsen Company has announced an agreement in principle to acquire the outstanding shares of BuzzMetrics, completing its purchase of the online tracking and analysis firm.

Financial terms of the deal were not disclosed. Nielsen currently owns 58 percent of BuzzMetrics.

Upon completion of the transaction, Nielsen//NetRatings and Nielsen BuzzMetrics will be consolidated into a single service unit under Itzhak Fisher, executive chairman of BuzzMetrics.

"NetRatings and BuzzMetrics are recognized as the two leading providers of insight about consumer behavior online," said David Calhoun, chairman and CEO of The Nielsen Company. "By acquiring 100 percent of these world-class brands, Nielsen can provide our clients with unrivaled understanding of consumer behavior in this space."