New York (CNN Business) Walgreens reportedly wants to go private, and KKR is said to be interested in buying it. The acquisition would almost certainly be the largest private takeover in history.

Walgreens Boots Alliance WBA Shares ofsurged 6% in early trading Monday on the report. According to Bloomberg , KKR has approached Walgreens about a deal. The buyout firm KKR is one of the world's largest private equity firms, and its leveraged buyout of RJR Nabisco was cataloged in the book, "Barbarians at the Gate."

Walgreens currently is valued at more than $55 billion. Any deal would probably be done at a premium to that price — and also include the assumption of the $16.8 billion in debt the retail and pharmacy giant has on its balance sheet.

KKR KKR Goldman Sachs GS Vistra Energy VST According to merger research firm Dealogic, the largest private takeover ever was the $44 billion acquisition (including debt) of Texas utility company TXU by, fellow private equity firm TPG andin 2007. TXU went bankrupt in 2014 but has since emerged from Chapter 11 protection and is now a part of the power company known as

Walgreens had no comment for CNN Business about the Bloomberg report or a Reuters report last week that said it is looking to go private. KKR was not immediately available for comment.