Hollywood superagent Ari Emanuel’s reputation as a legendary dealmaker is being put to the test.

Emanuel’s Endeavor has spent months trying to sell TV rights to the Ultimate Fighting Championship, the mixed martial arts league his company bought for about $4 billion in 2016 with the private-equity firms Silver Lake Partners and KKR. The buyers gambled UFC could obtain a huge payday from TV networks hungry for more live sports.

But no buyer has stepped up to pay the $300 million to $400 million a year Endeavor wants, people close to the talks said. 21st Century Fox Inc., which has the contract now, has expressed its interested in keeping the sport, and Endeavor is waiting to see if the company will increase its estimated $200 million bid, said the people, who asked not to be identified discussing the negotiations.

The negotiations are a big test for sports rights owners, who have managed to squeeze more out of the TV industry for years. In January, Fox Inc. agreed to pay a record $3 billion for five-year rights to Thursday Night Football. CBS and NBC, which had the games previously, concluded they couldn’t make money at the old rates. Meanwhile the audiences for live sports continue to shrink, and the price for England’s Premiere League soccer fell in the latest auction.

“It’s unlucky timing,” said Michael Colangelo, assistant director of the Sports Business Institute at the University of Southern California. “We see cord-cutters and people moving to digital. It’s a very weird time.”

Buying the UFC was Emanuel’s biggest investment in his bid to transform Endeavor from a talent agency representing stars Matt Damon into a media colossus with live events, streaming services, athletes and models all over the world.

With backing from Silver Lake, Emanuel spent about $2.4 billion buying IMG, which operates one of the largest sports agencies in the world and sells media rights to events like Premiere League soccer. He then acquired Professional Bull Riders and formed an e-sports league with Turner Broadcasting.

Yet none of the investments yielded the big prize: rights to a major sports league in the U.S., the world’s largest media market.

That search led to the UFC, which Emanuel already represented in negotiations. Fox agreed to pay an average of about $120 million a year for UFC TV rights in 2011, according to published accounts. In selling the company, the previous owners forecast the league could get more than $400 million a year in its next rights deal.

Endeavor has lowered its expectations in private, and sports-rights analysts say the company isn’t dependent on one market to justify the purchase price. The league has a large following overseas, especially in Brazil, and has scored significant increases in deals in the Middle East and Latin America.

As the current UFC broadcaster, Fox has been considered the frontrunner. UFC accounts for a sizable share of the programming on FS1, the company’s sports network. Fox had an exclusive window to negotiate a new deal, but that closed last year and the talks have slowed, according to the people.

Live sports have grown in importance for Fox since the company agreed to sell most of its film and TV assets to Walt Disney Co. The company has also explored a bid for the rights to World Wrestling Entertainment as an alternative.

WWE gets higher ratings than the UFC, which has lost viewers the past couple years. Fox’s UFC audience has shrunk more than 30 percent since 2015.

At the moment, UFC lacks a star of the magnitude of Ronda Rousey or Conor McGregor, according to Colangelo, and has spread itself thin. The most appealing matches go on pay-per-view, leaving less for Fox. But the league should bounce back. “The UFC is a cyclical business,” he said.

Endeavor is talking to other suitors, including tech and phone companies and traditional TV players, the people said. Amazon.com Inc. bought non-exclusive rights to pay-per-view matches, and Emanuel could split the other rights between a technology company and a media company. Facebook Inc., YouTube and Twitter Inc. have all acquired sports rights in the past couple years.

Emanuel would prefer one big deal that includes TV, which still offers the largest live audiences, two of the people said. Major media companies are creating sports streaming services to complement their TV networks. Disney is about to introduce ESPN+, while Turner and Fox are exploring new ventures as well. CBS Corp. also launched an online sports service last month.

Turner chiefs John Martin and David Levy have told several people they are interested in UFC, but their ability to bid is partly hampered by an ongoing government challenge to AT&T Inc.’s acquisition of their parent company Time Warner Inc. ESPN declined to comment, though several people familiar with the company’s plans said it was bidding.

“Live events are at a premium in the new media industry, and the UFC has a lot of them,” said Lee Berke, a sports media consultant who has worked with more than 30 professional sports team. “Even with the struggles on some platforms, overall they’ll still do very well.”