The FTC issued an official statement concerning its conditions for approving Nielsen's purchase of Arbitron, followed shortly thereafter by Nielsen issuing a press release about the deal being approved.
See both http://www.ftc.gov/opa/2013/09/nielsen.shtm and http://nielsen.com/us/en/press-room/2013/nielsen-gains-regulatory-approval-to-acquire-arbitron.html.
See both http://www.ftc.gov/opa/2013/09/nielsen.shtm and http://nielsen.com/us/en/press-room/2013/nielsen-gains-regulatory-approval-to-acquire-arbitron.html.