The launch involves DirecTV-7S, a geostationary satellite for the US digital multichannel television provider DIRECTV.

The satellite was initially to have been launched by an Ariane 5, which became the European Space Agency's standard rocket after the smaller Ariane 4 was phased out this year, Arianespace said.

However, "delays in the satellite manufacturing process created a scheduling conflict" with a big ESA scientific mission, the launch of Rosetta, a billion-euro (-dollar) comet-chasing robot probe, it said in a statement.

Launch of DirecTV-7S, which is designed to beam services to 60 local markets in the United States, will now be carried out by Boeing Launch Services and Sea Launch Company, a company which uses US, Russian and Ukrainian space technology to provide launches from a specially adapted ship.

Sea Launch is owned by Boeing (40 percent); RSC-Energia of Russiapercent); Kvaerner of Norway (20 percent); and SDO Yuzhnoye/PO Yuzhmash of Ukraine (15 percent).

Arianespace; Boeing Launch Services and Sea Launch; and Mitsubishi Heavy Industries of Japan, signed a three-way "launch services alliance" last July.

This is a cooperation agreement in which the companies agree to provide backup launches if one of their number cannot cope with an order.

Rosetta is due to lift off next February 26 for a rendezvous in 2014 with the comet Churyuamov-Gerassimenko, according to ESA.

The unmanned spacecraft was to have been launched last January on a 10-year mission to chase the comet Wirtanen and send a lander to analyse its surface, a first in the history of space exploration.

But the launch was scrapped as ESA carried out a reliability check of the Ariane-5 following the disastrous failure of a heavy version of this vehicle the previous month.

SPACE.WIRE