It was understood that the 21-year-old would join the Saints in a £12m deal this week, but Oscar Betancourt has revealed that the transfer is now off.
"The negotiations with Southampton have ended. I have spoken today with the English club's chairman and they are looking at another target," he told calciomercatoweb.it.
"Bologna didn't want to close the deal without the bank guarantees. The player was very happy with the offer received, but now he will probably remain at Bologna.
"Tottenham is an option to be rejected at this time because they are a long way short of Bologna's demands. Liverpool? They have never presented a concrete offer."
Ramirez has nine Uruguayan caps to his name.