Vermaelen, who is also reported to be wanted by Barcelona, had been linked with a move to Old Trafford but it is understood Arsenal were not prepared to sanction a direct sale to United.
New United boss Louis van Gaal wanted to bring in the Belgian defender to add experience to his squad following the summer departures of Rio Ferdinand, Nemandja Vidic and Patrice Evra.
Earlier this week Arsenal boss Arsene Wenger gave a strong hint that Vermaelen would be leaving and that United was a possible destination.
Speaking at a press conference ahead of Sunday’s Community Shield with Manchester City at Wembley, Wenger admitted there had been interest in his captain but refused to reveal who had been in touch, although he did confirm United “could be in the group”.
"Have we received bids? Yes. I can't tell you who from but you will know very soon," he said. "Are Man United one of the teams to have made an offer? I think they could be in the group."
"Ideally, yes, we would like to sell him abroad and that is an option for us.
"I don't want to say how many offers we have but we have offers from abroad as well."
Vermaelen has been at Arsenal since 2009 and remains their official club captain, but he was not a regular started last season as Wenger preferred to partner Laurent Koscielny and Per Mertesacker together in central defence.
Wenger believes it is important for Vermaelen to play, saying: "He could leave, it could happen, I've said that since the start of pre-season.
“He needs to play now. He has shown an outstanding attitude but he is in a position where we wouldn't stand in his way if he finds an interesting opportunity."