Sir Alex Ferguson has revealed Manchester United have hit a brick wall in their attempts to sign Robin van Persie from Arsenal. Ferguson revealed on United's recent tour of South Africa United had made a bid for last season's Premier League Golden Boot winner. The Red Devils interest seems to have fended off competition from Manchester City and Juventus. However, Arsene Wenger has never sold a player to United. And, from Ferguson's comments to reporters following Wednesday's penalty shoot-out defeat to Barcelona in Gothenburg, it doesn't appear he wants to start now. "We have made a bid and they've been trying to negotiate with other clubs," said Ferguson. "I don't have a gut feeling on it at the moment, I must admit. "We're not getting any breakthrough with Arsenal. It's difficult to say why they're operating this way. I don't know what their thoughts are because they're not giving anything away." There had been rumours circulating prior to the Barcelona game that Van Persie was heading to Manchester for a medical. It seems they were wide of the mark. "I can't give you any more information," said Ferguson. "We just have to persevere. We are trying our best and hopefully it will come our way but there's no progress at this moment in time." United miss out on Moura It was the second transfer blow of the day for United, who discovered prior to kick-off that Brazilian midfielder Lucas Moura had joined cash-rich Paris St-Germain. Ferguson was keen to sign the teenage midfielder from Sao Paulo and remained in Manchester at the weekend when his team headed to Norway "to do some business". The clearest indication Moura was looking elsewhere was that Ferguson jetted out of Manchester prior to Brazil's Men's Olympic Football Tournament semi-final win over Korea Republic, when the midfielder was an unused substitute. It seems United simply could not compete with PSG's Qatari-backed spending power. Following the huge purchases of Zlatan Ibrahimovic and Thiago Silva, Ferguson stated the world had 'gone mad'. "I find it quite amazing that a club can pay €45 million for a 19-year-old boy," said the Scot. "To tell everyone that PSG are here they've signed Thiago Silva and Zlatan Ibrahimovic. They must have spent about £150m in the last month. "The only deterrent to that is UEFA. In the conditions of European football, you don't qualify for Europe by winning the league or coming second - you only get in by invitation. "That's where, hopefully, UEFA can have some power. When somebody's paying £45m for a 19-year-old boy you have to say the game's gone mad."  FIFA