Ferguson added that he did not think, in the wake of the £32 million ($58 million) transfer of Mario Gotze, that Dortmund would also sell Lewandowski to Bayern.
"Dortmund fans are not going to be happy and I don't think they will sell Lewandowski to Bayern Munich," Ferguson said.
"I think they'll let his contract run out, or sell him somewhere else," said the United manager.
Bayern are now planning to formalise efforts to tempt Suarez away from Anfield.
Liverpool have insisted the 26-year-old Uruguayan will not leave the club this (northern) summer, despite him being hit with a 10-game suspension for biting Chelsea defender Branislav Ivanovic.
While Suarez has told teammates that La Liga, rather than the Bundesliga, is his preferred destination should he leave Liverpool, the impending arrival of Pep Guardiola as Bayern coach could prove decisive.
Guardiola has made no secret of his admiration of Suarez, who is represented by Pere Guardiola, the former Barcelona coach's brother.
Manchester City also retain an interest in Suarez, but the player's reputation could trouble the club's image-conscious Abu Dhabi ownership.
Juventus are also monitoring his situation.