Sued for Using 'Eye Of the Tiger'

Newt Gingrich is being sued by the company which owns the rights to the 1982 song, "Eye of the Tiger" -- claiming Newt had no right to use it as part of his campaign.

Rude Music Inc. -- owned by a member of the band Survivor -- filed the suit today in federal court in Illinois ... claiming Newt has jacked the song made famous in "Rocky III" to push his political agenda.

According to the lawsuit, Newt has been using the song at various political events since 2009.

In the suit, Rude Music claims Gingrich used the song at the Conservative Political Action Conference in 2009, 2010 and 2011 ... as well as the Southern Republican Leadership Conference in 2010.

RMI claims Gingrich -- along with his campaign team, Newt 2012, Inc. -- recently used the song during a campaign event in Doylestown, Pennsylvania ... claiming, "Mr. Gingrich entered the packed Moose Lodge for a speech as the song 'pulsed,' according to the the Newt 2012, Inc. website."

RMI is also suing the American Conservative Union -- claiming it has republished various clips featuring Newt and the "Eye of the Tiger" song without permission.

RMI is asking a judge to order Newt and his team to stop using the song ASAP -- plus, the company wants unspecified damages.

Gingrich isn't the first G.O.P. candidate to be sued for using music -- back in 2008, Jackson Browne sued John McCain for using the song "Running on Empty" in a political ad.