Three people familiar with the hire confirmed Wednesday that Terry and Kim Pegula have retained Steve Greenberg, of Allen & Co., which is regularly involved in sales of sports teams.
The Pegulas have not publicly said whether they will try to buy the NFL team, which is on the market after the team's owner and founder, Ralph Wilson, died in March. But The Associated Press has reported the Pegulas were among prospective buyers who received a nondisclosure agreement and background on the Bills from a law firm representing Wilson's estate.
The people who confirmed Greenberg's hiring spoke on the condition of anonymity because the Pegulas have not announced it. The move was earlier reported by The Buffalo News on its website.
The Pegulas made their fortune in the natural gas industry, after Terry Pegula sold off many of his company's assets for $4.7 billion to Royal Dutch Shell in 2010.
The Bills were last valued by Forbes to be worth $870 million but their sale price could go much higher because NFL teams rarely go on the market.
The franchise's current lease essentially ties the Bills to playing at their current stadium through the 2019 season, but there are concerns the team eventually could relocate to another city or state or perhaps Canada under a new owner.
A Pegula spokesman issued a statement last month saying the Pegulas "have a strong desire to have the Buffalo Bills remain a centerpiece of this region."
But the statement stopped short of saying whether the Pegulas would try to buy the team.
Prospective buyers are awaiting a full valuation of the franchise from investment firm Morgan Stanley before the bidding process begins.
One of the people told the AP that the valuation has yet to be distributed.