The rocket was successfully launched from the Baikonur space center in Kazakhstan at 01:48 Moscow time (21:48 GMT)
"The Nimiq-4 satellite was successfully orbited," a source in the Khrunichev State Research and Production Center said.
The contract to launch the satellite was signed last April by Canada's satellite communications company Telesat and International Launch Services (ILS), a U.S.-Russian joint venture with exclusive rights for worldwide commercial sales and mission management of satellite launches on Russia's Proton rockets. Since 1996, ILS has carried out 47 commercial launches of Proton rockets.
Nimiq-4 was build by Astrium, a subsidiary of the European Aeronautic Defense and Space Company (EADS), to provide high definition television (HDTV) in North America. The satellite has a life span of 15 years.
The launch of the next Nimiq-series satellite to be built by U.S. company Space Systems/Loral is scheduled for 2009.