The 18-year-old was expected to complete his £10 million switch in January but the deal hit a stumbling block and the Red Devils opted against signing the Serbian playmaker.
A United spokesman claimed Ljajic had failed to make significant improvements in the previous 12 months, while other reports suggested the club pulled the plug due to financial problems.
However, assistant manager Mike Phelan recently quelled these rumours, confirming the move broke down after the club failed to secure a work permit for Ljajic.
The Serbian was due to team-up with Zoran Tosic – who arrived from Partizan as part of the deal last season – and has hit back at claims Sir Alex Ferguson pulled out of the deal because his development had stagnated.
“Stories about stagnation in my football development are nonsense,” he told Serbian newspaper Danas.
“If Manchester United were really not satisfied with how much I’ve progressed in this year, I would not have been with Ferguson two months ago at the end of my last cycle of mandatory training at the club before moving to England.
“The reason for the transfer not happening is that I couldn’t get a business license.”
The collapse of his transfer to the Premier League has alerted a number of interested clubs and Ljajic admits his Partizan future remains in serious doubt.
“Who knows what I will do next?” he said.
“I have heard already that clubs are interested and that Partizan want to sell me. We’ll see.”
