Greenedge spokesman Neil Stephens said the team was "distraught" about the loss of Dean.
"From a sporting perspective, it's terrible to lose a rider to a crash. From a personal perspective, we really feel for him. He has had a lot of bad luck this year and Catalonia was his first race back after a previous injury.
"He'll have an operation tonight in Valencia - his home base in Europe. We preferred for him to have surgery at home to make things easier for him and his family," Stephens said.
Prior to the race a number of riders pulled out of the tour including RadioShack-Nissan's Andy Schleck and Moviestar's Alejandro Valverde. Organisers cut short the stage before the final two climbs of the day as snow, wind and rain hit the peloton.
Dean won a bronze medal on the track at the 1994 Commonwealth Games and also competed at Atlanta in the team's pursuit but switched to the road for the 2000, 2004 and 2008 Olympics.
He had been expected to team up with Greg Henderson or Hayden Roulston for the road race at London but his probable unavailability might open the door for someone like Jack Bauer or allow BikeNZ to enter one of the track riders to beef up their track team.
Fellow Kiwi Sam Bewley tweeted: "Heart sunk as I just read a tweet that Julian Dean has broken his leg. Too many bad things happen to too many good guys! All the best Jules!"
- APNZ