The Federal Trade Commission closed a non-public investigation into the Ultimate Fighting Championship's purchase of Strikeforce last week and will take no further action in the case.

Documents published on the FTC website dated January 25, confirm the FTC's Bureau of Competition conducted an investigation to determine whether the $34 million acquisition of Explosion Entertainment, LLC, by UFC's parent company, Zuffa LLC, violated Section 7 of the Clayton Act or Section 5 of the Federal Trade Commission Act.

In closing letters issued to counsel for Zuffa and Explosion Entertainment, FTC secretary Donald S. Clark stated, "Upon further review of this matter, it now appears that no further action is warranted by the Commission at this time. Accordingly, the investigation has been closed."

Zuffa purchased Explosion Entertainment from Scott Coker and Silicon Valley Sports and Entertainment in March 2011 and has since promoted 12 events under the Strikeforce banner.

Since Zuffa took control, Strikeforce and Showtime reached a new programming agreement that calls for up to eight live events to air in 2012.

Josh Gross is a mixed martial arts writer for ESPN.com.