WPP, one of the world's largest ad agencies, plans to buy the digital marketer for $649 million.
WPP's announcement on Thursday comes just one month after Google said it will acquire online ad company DoubleClick in a $3.1 billion deal. Google's deal led to speculation that there would be an acquisition boom in the advertising technology market. Earlier this month, there were rumors that Microsoft would buy 24/7.
The deal will tie WPP's traditional mix of marketing, advertising, public relations and branding with 24/7's search-based ad serving, monitoring and analytics technologies.
"Our clients and therefore our industry are becoming more technology driven," Martin Sorrell, WPP chief executive, said in a statement. "24/7 Real Media significantly enhances our capabilities, technological resources and talent."
With 24/7, London-based WPP aims to enhance its clients' abilities to target and reach customers via search marketing, online display advertising and sophisticated ad management tools.
Under the deal, WPP will pay $11.75 for each share of New York-based 24/7. Shares of 24/7 rose 3.8 percent to $11.69 in morning trading.
The deal is expected to close in the third quarter.