Sources quoted by mergermarket.com said: "CVC/ Cinven is the only consortium bidding without an existing pubs management, so it's natural that Scottish & Newcastle management would chose CVC/Cinven to ally with."
Another said CVC/Cinven might be in the auction to work the incumbent management angle and "to keep the other bidders honest".
The sources added that they were sceptical about CVC/Cinven's chances of success, saying: "I cannot see how they can win without over-paying."
Scottish & Newcastle said: "Management will not align themselves with any bidder until the bidding process is over." Nonetheless, it said, "S&N have a very highly regarded management team that any of the bidders would value, whether they have existing management teams or not."
Speculation has previously linked the private equity houses to Spirit's bid for the pub chain.