Nokia could not be reached for comment, but an executive familiar with the situation said media "remains at Richards for right now."
MediaCom could not immediately be reached.
Independent Richards Group had handled media as well as advertising since 1997. The Dallas-based agency declined to comment on a media move but has a policy of not defending accounts.
Nokia tapped MediaCom's sibling DarkGrey, New York, to handle its advertising after a review. A Grey spokeswoman declined to comment as well.
Nokia spent $57.8 million on measured media in the first 11 months of last year and $37.5 million in 2002, according to TNS Media Intelligence/CMR.