Froch won the title in May with a blistering fifth-round stoppage on home soil in Nottingham, but the deal is reported to have come with a rematch agreement should Bute lose.
Froch will make his first title defence next month against Yusaf Mack but plans for a return bout with ‘Le Tombeur’ in his native Montreal could be hindered by the IBF’s decision to name Adonis Stevenson as their number one contender.
Haiti-born Canadian Stevenson, 35, has a record of 19 wins and one defeat in 20 career bouts after winning middleweight silver at the 2006 Commonwealth Games in Melbourne.
And ‘Superman’ Stevenson claimed recently that Froch will have "six months" to fight him as mandatory challenger should he see off Mack in Nottingham on November 17.
“I’m the number one contender. Carl Froch has six months to fight with me”, Stevenson told World Boxing News.
“I don’t have a problem to go to Oakland. I don’t have a problem to fight Andre Ward.
“But Ward is negotiating with Kelly Pavlik right now and we have the number one spot for Froch’s title.
“But if Andre Ward wants to fight, he knows my number.”
Froch, also 35, is believed to regard second fights with Bute, Ward and Mikkel Kessler – the latter two being the only defeats on his 29-2-0 professional record – as his only remaining goals before retirement.
But should he pursue Froch-Bute II in Canada for spring 2013 over a Stevenson title challenge, he may end up doing so in a non-title contest.
Bute’s first fight since the championship loss comes on November 3 against Denis Grachev.