"We're excited to have another talented player in the mix for our defensive staff to work with," Giants general manager Jerry Reese told the team's official website. "We try to create competition at every position, and Keith will definitely bring some competition to our linebacker group."
A league source told NFL Network insider Jason La Canfora about the deal Wednesday The Giants didn't disclose which draft pick they gave up for Rivers, but the Bengals confirmed it was a fifth-round choice (167th overall).
In New York, Rivers will join a linebacker corps that includes Michael Boley, Greg Jones and Mathias Kiwanuka.
"I'm excited to get a fresh start and brand new-beginning," Rivers told the Giants' website. "You can't ask for more than to be playing for the defending world champions and be in New York."
"This is an excellent opportunity for him to have a fresh start," Coughlin said. "Keith is versatile enough to play the outside on first and second down, and he can play on third down because he runs well. And he's fast enough to rush the passer."
Rivers, the No. 9 overall pick by the Bengals in the 2008 NFL Draft, started 33 of 35 games in his first three years in Cincinnati, recording two sacks, two interceptions, seven passes defensed and a forced fumble in that time. He spent the entire 2011 season on injured reserve after July wrist surgery.