The Poland international was being mooted for a move to Bundesliga rivals Bayern Munich, who have already captured his Dortmund team-mate Mario Gotze.
Lewandowski further enhanced his reputation this week when he scored all four of his side's goals in the 4-1 Champions League win over Real Madrid.
Ferguson has confirmed he is a fan of the 24-year-old and is hoping Dortmund's reluctance to sell any more of their players to Bayern may work in United's favour.
"If the right player comes along you have to be prepared to make a move," the Old Trafford boss was quoted as saying on the Guardian's website.
"I can find room for anybody here as long as they have the required quality.
"I am not sure Lewandowski will be sold to Bayern now. The Dortmund fans are not going to be happy and I don't think they will sell to their main rivals.
"I think they will either let his contract run out or sell him somewhere else."