In a move the company calls a strategic transaction, the Nielsen Company Tuesday traded media rates and data provider SRDS to U.K.-based ad agency the WPP Group in exchange for the remaining 50 percent stake in AGBNielsen Media Research, making Nielsen the group’s sole owner.

As part of the asset swap, Nielsen will transfer healthcare media group PERQ/HCI—which merged with SRDS IN 2002—and its 11 percent stake in Brazilian-based research firm the IBOPE Group to WPP.

The deal was a “strategic transaction” for both companies, a Nielsen spokesperson told FOLIO:, indicating that SRDS is a “strong” business the company was not necessarily looking to sell. “SRDS is good fit for the Kanter Group [WPP’s research consultancy network],” the spokesperson said. “For Nielsen, this gives us full ownership of AGBNielsen Media Research, which covers TV ratings in 30 markets, which generates 60 percent of the world’s TV advertising.”

Nielsen owns Nielsen Business Media, which publishes b-to-b titles including Adweek, Brandweek and Mediaweek.

"In an increasingly digital world, it is essential for Nielsen to strengthen its global market position," Nielsen chairman and CEO David Calhoun said in a statement. "As a fully integrated part of our company, AGBNMR will be an important part of our portfolio and better positioned to offer high quality measurement for its clients.

Last month, the WPP Group acquired [1] TNS Media Intelligence parent Taylor Nelson Sofres for $1.9 billion.