The price of the Carolina Panthers has reached US$2.5 billion, according to people familiar with bids for the NFL team, which would set a record for a U.S. professional sports franchise.

The rapid escalation in bidding has prompted Michael Rubin, the billionaire executive chairman of sports-apparel company Fanatics, to drop out of the process, said the people, who requested anonymity because the matter is private.

A spokesman for Rubin declined to comment. His backers included Brooklyn Nets investor and Alibaba Group Holding Ltd. Executive Vice Chairman Joe Tsai.

Remaining bidders include Alan Kestenbaum, chief executive officer of private equity firm Bedrock Industries LP, leading an investor group that the people said is backed by Canada’s third-richest person, billionaire Jim Pattison.

However, BNN confirmed with a spokesperson for Pattison he has "no interest whatsoever” in backing the bid. 

Appaloosa Management LP founder David Tepper, already a minority owner of the National Football League’s Pittsburgh Steelers, has also submitted a bid. So has Ben Navarro, CEO of Sherman Financial Group, a South Carolina-based finance company that caters to subprime borrowers.

Also looming over the deal is interest from local billionaire Jim Goodnight, CEO of SAS Institute Inc., the people said. Goodnight has a net worth of $9.9 billion, according to the Bloomberg Billionaires Index, while Pattison is worth $7.5 billion.

A spokeswoman for Goodnight declined to comment. Steve Greenberg, the Allen & Co. banker overseeing the sale of the club, also declined to comment.

Panthers owner Jerry Richardson put the team up for sale in December after the NFL took over an investigation into workplace harassment allegations against the longtime owner.

Forbes values the Panthers at $2.3 billion, No. 21 on its list of 2017 NFL franchise valuations and worth about half as much as the top team on the list, the Dallas Cowboys.

-- With files from BNN