Gers desire impressed Prso
Prso was also wanted by Premiership duo Portsmouth and Bolton, but the Croatian plumped for The Gers after being impressed with the club.
"When I saw how they acted I was really charmed," said Prso - who has been a key figure in Monaco's UEFA Champions League campaign.
"They put a private jet at my disposal and went to extraordinary lengths to make me feel welcome.
"Straight away I had a great feeling about the coach Alex McLeish. It was really impressive.
"I am joining a great club and I am very, very happy.
"I honestly thought I would remain with Monaco, but they just could not compete. There are too many financial problems and I could not wait forever.
"I wanted things settled before I went to Euro 2004."
Prso has played at Ibrox before, featuring for Monaco against Rangers in the 2000 Champions League.
"During the entire encounter it was a great thrill," added the striker.
"The atmosphere was incomparable. I have never felt anything so strong in any other club in Europe.
"That is the kind of club I needed."
