Nielsen said it expects the deal to add about 13 cents per share to its adjusted earnings a year after closing and about 19 cents per share to adjusted earnings two years after closing.
Abitron's chief operating officer, Sean Creamer, is set to take over as CEO from William Kerr on Jan. 1. Calhoun said he hoped Creamer would remain with Nielsen after the deal closes.
Nielsen said it has a financing commitment for the transaction.
Nielsen was the prime source of audience ratings in the early days of radio, thanks to a device similar to Arbitron's People Meter. The Audimeter was attached to the radio set. The company's focus shifted to TV measurement in the 1950s.
On Monday, Nielsen announced a deal with Twitter to measure how much U.S. TV watchers tweet about the shows they're watching. The "Nielsen Twitter TV Rating" will debut in the fall.