On Tuesday, Nielsen Holdings (NLSN) announced it will acquire all outstanding shares of international media and marketing research firm Arbitron (NYSE: ARB) in an all-cash transaction, paying $48 per share. The boards of both companies have already approved the merger.

In a statement on the $1.2 billion merger, Nielsen boasted of the "unique radio measurement and listening information" that Arbitron will bring to Nielsen, and how bringing the two companies together will "enable broader measurement of consumer media behavior in more markets around the world."

Together, Nielsen says the company will generate $6 billion in combined annual revenue, with earnings before interest, taxes, depreciation, and amortization amounting to approximately $1.7 billion. Nielsen further says it expects to find $20 million worth of "cost synergies" that can be cut once the merger is complete.

Shares of Arbitrion were up nearly 24% in response to the announcement at $47.01 per share. Nielsen's shares, too, moved up 4% at $30.80.