We told you last week that sources were reporting that Shane Mosley-Manny Pacquiao was headed to CBS/Showtime PPV.

Well, the deal is official, and is being hyped as “the biggest boxing event of the year.”

(Have they not seen Mosley fight recently?)

“The arrangement with CBS and Showtime regarding the promotion and distribution of the Pacquiao vs. Mosley championship event represents a new opportunity for the sport of boxing,” said Top Rank CEO Bob Arum. “It enables boxing to reach millions more people in the United States given the reach of CBS, the most watched television network in the country. This development will not only benefit Manny Pacquiao and Shane Mosley but all of the young men participating in the sport of boxing.”

Mosley-Pacquiao marks the first Showtime PPV event since Diego Corrales vs. Jose Luis Castillo II in 2005.

“We look forward to combining Showtime Sports’ production and distribution expertise with Top Rank’s promotional power and the amazing programming and marketing resources available to us across CBS to present the biggest boxing event of 2011,” said Ken Hershman, Executive Vice President and General Manager, Showtime Sports.