PARIS — The Mexican Communications and Transport Ministry has contracted with Europe’s Arianespace consortium to launch the Mexsat 3 satellite in late 2012 as a co-passenger aboard a heavy-lift Ariane 5 rocket or as the sole passenger on a Europeanized version of Russia’s Soyuz vehicle, Evry, France-based Arianespace announced Sept. 29.

The contract was signed in June, the Mexican ministry said.

Mexsat 3 is under construction by Orbital Sciences Corp. of Dulles, Va., as part of a three-satellite program managed by Boeing Space and Intelligence Systems of El Segundo, Calif., for the Mexican government.

The program includes two large Boeing-built mobile communications satellites, Mexsat 1 and Mexsat 2, and the smaller Mexsat 3, which Boeing hired Orbital to build.

Mexsat 3 is expected to weigh about 3,050 kilograms at launch, putting it near the limit of what the Europeanized Soyuz can carry into geostationary transfer orbit from Europe’s Guiana Space Center in French Guiana. Soyuz flights are scheduled to begin Oct. 20 from the European spaceport.

Mexsat 3 will be equipped with 12 extended-C-band transponders and 12 transponders in extended Ku-band. It will operate at 114.9 degrees west for a scheduled 15 years, and is designed to provide 3.5 kilowatts of power to its payload.

Peter B. de Selding was the Paris bureau chief for SpaceNews.