Financial terms of the deal were not disclosed.
Montador, 31, had a career-high 21 assists and 26 points with the Buffalo Sabres last season. He also led the team with a plus-16 rating and 136 blocked shots.
His signing comes less than 24 hours after the Blackhawks acquired him from the Buffalo Sabres in exchange for a seventh round draft pick in either the 2012 or 2013 NHL Entry Draft.
(Reporting by Gene Cherry in Raleigh, North Carolina; Editing by Frank Pingue)