Valentino Rossi’s tipped $20-million deal to join the Ducati Marlboro Team in next year’s MotoGP World Championship is a done deal according to weekly British magazine Motorcycle News.

The article, penned by well-informed GP journalist Matthew Birt, indicates that the deal is signed and sealed, a move which will see 31-year-old Rossi join the Italian team for what are expected to be his final seasons in grand prix racing.

It’s the story that has rocked the industry this week, a switch from Fiat Yamaha that has been speculated for months, and MCN says that the deal could be confirmed as soon as this weekend’s Catalunya Grand Prix in Spain.

“I know for sure that Rossi will go to Ducati next season,” an unnamed ‘senior GP figure’ confirmed to Birt. “The deal has been done. One month ago it seemed impossible to imagine this, but Rossi will be in red next year.”

It’s believed that Rossi signed the deal on the weekend of his championship-ending crash at Mugello’s Italian Grand Prix last month, The Doctor ruled out with a broken leg after his mega crash during Saturday’s practice, although he’s expected to return to racing at Brno in August.

The reason for Rossi’s eventual switch is said to have came after he’d agreed to terms with Yamaha despite a pay cut, however that deal turned sour at the 11th hour as Rossi learned that world champion elect Jorge Lorenzo would be receiving a pay rise to remain on the YZR-M1 in 2011.

Rossi’s unconfirmed two year deal has opened up the door for Silverstone podium finisher and current Superbike World Champion Ben Spies to move alongside Lorenzo in the factory Fiat-supported team, vacating his seat in the satellite Monster Tech 3 Yamaha squad. Spies’ current teammate Colin Edwards is also tipped for retirement at the close of the season, opening up two of the most sought after seats in the paddock.

American 2006 world champion Nicky Hayden is believed to be on the verge of signing a contract extension to partner Rossi at Ducati, while the marque’s only premier class world champion Casey Stoner is all but confirmed to be returning to Honda for next season.

If confirmed, 2007 series champion Stoner will be joining the factory Repsol team on an RC212V alongside Spaniard Dani Pedrosa, while Italian Andrea Dovizioso could be onboard a Red Bull-supported third factory bike in the team.

It is expected that Rossi’s current crew lead by Australian guru Jeremy Burgess will depart Yamaha with him to race in red for next season, however that also remains unconfirmed at this point.

Watch this space.