(Adds UFC president denying sale)

May 10 (Reuters) - The owner of Ultimate Fighting Championship (UFC) is exploring a sale of the promotion company that popularized cage fighting, according to an ESPN report that UFC's president later denied on Tuesday.

Dana White, UFC president, later told The Las Vegas Review-Journal that UFC was not for sale and called the ESPN report "overblown."

ESPN earlier reported that UFC's parent company, Zuffa LLC , which is controlled by casino moguls Frank and Lorenzo Fertitta, had hired an investment bank to advise it on a sale that could value the company at $3.5 billion to $4 billion. (http://es.pn/1OfWFJw)

ESPN said that interested bidders were WME IMG Holdings, a media and talent agency that represents sports stars and celebrities, along with two Chinese firms China Media Capital and Dalian Wanda Group, and U.S. private equity firm Blackstone Group LP.

The firms ESPN said were exploring bids for UFC declined to comment or did not return requests for comment.

UFC, which features a blend of fighting styles, was founded in 1993 and holds more than 40 fights per year around the world, according to its website.

Live events and sports brands are some of the most attractive and fast-growing areas of the media industry.

(Reporting by Natalie Grover in BENGALURU and Liana B. Baker in SAN FRANCISCO; Editing by Sandra Maler)