The singer, who finished in second place in last night's final, will be signed to Simon Cowell's Syco label and release an album, the Sunday Mirror reports. Advertisers and promoters are also said to be keen to sign him up.
Showbiz agent Jonathan Shalit said: "The natural path will be for Simon's company Syco to throw together an album of cover hits to get it in the shops as soon as possible. Then there are personal and public appearances, commercial deals and endorsements to think about - where Ronan could bring in a lot of money indeed. You're talking hundreds of thousands of pounds.
"His story in a book would work well and magazine deals would work for an initial period too. He's a young kid and girls will find him cute, parents will love his clean-cut image and he's perfect for the teen market if you get the songs right.
"The only problem you have is what will happen once his voice breaks? Will he still have an incredible voice? Only then will somebody like Simon Cowell be able to morph Ronan into the next Justin Bieber. Until you know what you're working with, you can't even begin to plan a long future."
Cowell was recently forced to deny allegations that Britain's Got Talent had been fixed for Parke to win.
> Britain's Got Talent final: Pictures
> Ant & Dec: 'Jai McDowall win disproves fix claims'