The bidding for the Buffalo Bills is set to begin now that prospective ownership groups are being contacted by a law firm representing late owner Ralph Wilson's estate.

Two people familiar with the sale process told The Associated Press on Thursday that prospective buyers began receiving a seven-page non-disclosure agreement, and a brief outline of background material on the Bills franchise and stadium. The documents were distributed by Proskauer Rose, the legal firm overseeing the sale.

Both people spoke on the condition of anonymity because the sale process has not been made public.

Real estate mogul Donald Trump released a statement confirming he has received the documents.

NHL Buffalo Sabres owner Terry Pegula has also received the documentation, one of the people said.

Pegula's entry marks the first clear signal of his interest in getting involved in buying the NFL franchise, which is going on the market after Wilson died in March.

The Toronto Sun first reported on its website Thursday that the documentation was distributed.

A full list of candidates is unknown.

Former Sabres owner Tom Golisano has expressed interest in buying the Bills. Another prospective group could include Toronto-based businessmen Larry Tanenbaum, chairman of Maple Leaf Sports and Entertainment, and Edward Rogers, deputy chairman of Rogers Communications.

The next step is for prospective owners to sign the non-disclosure agreement, one of the people said. That would then provide groups full access to the Bills' financial data in order to begin formulating bids.

The bids will be submitted to Morgan Stanley financial advisers, a banking firm also hired by Wilson's estate.

Morgan Stanley will be responsible for receiving the bids and vetting each group's background and finances before recommending a candidate to the NFL, one of the people said. The firm has an extensive history in working with the league, and its oversight in vetting candidates is expected to speed the sale process.

People familiar with the sale have previously said an ownership candidate could be identified by the end of July, and the sale approved by NFL owners as early as the league's meetings in October.

Pegula's entry into the Bills sale process doesn't come as a major surprise.

He previously said he wouldn't want to see the Bills relocate outside of western New York under a new owner. But he had never said whether he would get involved in a bid to purchase the team.

Pegula's net worth was last estimated by Forbes to be $3.3 billion. He's from Pennsylvania and made his fortune after selling many of his natural gas company's assets for $4.7 billion to Royal Dutch Shell in 2010.

Pegula's net worth could rise after his company reached a deal to sell off 75,000 acres of land in Ohio and West Virginia to Oklahoma-based American Energy Partners last week.

Trump's net worth was last estimated by Forbes to be $3.9 billion, though his advisers have said he's worth far more.

Trump released a statement saying he will make a decision regarding his interest in buying the team based on the financial details he receives from Morgan Stanley. Trump didn't rule out making the bid on his own or part of what he called, "a syndicate."

The Bills sale has raised concerns that the team could eventually relocate, with Toronto and Los Angeles considered potential landing spots.

The Bills, however, are essentially tied to playing at Ralph Wilson Stadium through the 2019 season under terms of their lease agreement.