Barry Diller has resigned as chairman and chief executive of Vivendi Universal's entertainment arm.
Mr Diller is thought a possible bidder for Universal Studios himself
The move was not unexpected as the French media and utilities giant is looking for buyers for its US entertainment business.
The assets include Universal Studios and Universal's theme parks.
Vivendi built up huge debts acquiring a string of media companies during the dot.com boom.
Once-lauded boss Jean-Marie Messier was forced to step down following criticism of his strategy and management style.
New management, headed by Jean-Rene Fourtou, has concentrated on reducing debt by selling off assets.
Earlier this month, Vivendi reported an annual loss of 23.3bn euros (£15.9bn; $25.5bn) - the largest loss in French corporate history.
The writing-off of assets once valued much more highly was a big contributor to the net loss.
Before joining Vivendi, Mr Diller was chief executive of a succession of media and internet companies.
From 1984 until 1992, he was chairman and chief executive of Fox, overseeing the film firm's move into broadcasting.
"My executive role [at Vivendi] was never intended to be permanent," Mr Diller said.
"Now that Vivendi Universal has begun a formal process in reviewing options for its entertainment assets, it is appropriate to step aside from any direct management responsibility."
Potential buyers include fellow media giants Viacom and MGM and former oilman Marvin Davis.
Mr Diller himself is reported to be interested in bidding for Universal Studios.
Mr Diller remains chief executive of USA Interactive, which runs businesses including the Home Shopping Network, Ticketmaster and online travel firm Expedia and owns 5.4% of Vivendi Universal Entertainment.
It was also announced on Wednesday that USA Interactive was buying out the share of Expedia that it did not already own in a $3.3bn deal.
Shares in Expedia rose 21% while USA Interactive dropped 8%.