Bidding to buy the UFC is drawing closer to an end, sources told ESPN on Thursday.

The two bidding groups -- WME-IMG in conjunction with Dalian Wanda Group, and China Media Capital -- had similar bids in the $4.1 billion range, sources said.

Sources said that both bidding groups are still trying to completely finance the buyout, which would be for the entire company. Which company ultimately wins out might depend on the details of that financing. Sources say WME co-chair Ari Emanuel has been asking well-heeled investors to chip in between $25 million and $50 million.

One of those investors that said yes, according to sources, was the Kraft Group, which owns the New England Patriots and the New England Revolution. A Kraft Group spokesman declined comment.

The WME-IMG bid with Dalian is also said to include China's Tencent Holdings, one of the 10 largest internet companies in the world and ESPN's official digital partner in the region. State-backed investment firm China Media Capital has been bankrolling many projects, including a five-year broadcast-rights deal with China's top-tier soccer league worth $1.3 billion.

Reached Thursday, UFC president Dana White said he had no comment.

Last month, ESPN reported that the entire UFC organization was actively up for sale and that bids were in the $3.5 billion to $4 billion range.

At the time, White denied that Zuffa, which bought the UFC for $2 million in 2001, was in an active bidding process.

Sources say that although White denied details of the sale publicly, the UFC forced partners to sign more extensive confidentiality agreements after the leak.

Zuffa, a company set up by brothers Lorenzo and Frank Fertitta, owns about 80 percent of the venture, and Abu Dhabi's Flash Entertainment bought a 10 percent piece for an undisclosed sum in 2010. White, who is expected to be asked to stay in some capacity should a sale go through, also has a share.

While the UFC has developed into quite a business, with a rights deal on the horizon that could very well double to more than $200 million a year beginning in 2019, the business is volatile. The UFC has kept its financial cards close to its vest, but Lorenzo Fertitta told CNN that the business grossed about $600 million last year.

The UFC is undoubtedly coming off its best year thanks to the emergence of Conor McGregor and Ronda Rousey, but the return of Rousey -- who is represented by WME-IMG -- is uncertain, and both fighters are facing the prospect of their second losses in as many bouts. With both out for UFC 200, the brand was forced to make a big move to ensure that the event had some shine. It worked with Brock Lesnar to set up his one-off return to the Octagon despite his WWE contract.

Dalian Wanda has recently invested in more sports properties. Last year, it bought a 20 percent stake in soccer superpower Atletico Madrid for $48 million. In March, the company became a top-tier FIFA sponsor through 2030.