A powerful Republican congressman is concerned about media consolidation and is looking for some answers.

Rep. Joe Barton (R-Texas), the ranking Republican on the House Energy & Commerce Committee, wrote Yahoo CEO Jerry Yang to say he is concerned with consolidation in the online-advertising industry and how its partnership with Google could affect competition.

Google said last week that it would give Yahoo nonexclusive access to its AdSense ad-display technologies for search and content advertising -- translation, Google ads would run on Yahoo, too -- and work to make their respective instant-messaging services more interoperable.

To read the article, click here [1].