PARIS — Satellite fleet operator SES’s four-satellite order with Astrium Satellites, valued at more than 500 million euros ($755 million), includes three high-power satellites offering 60-plus Ku-band transponders each to reinforce SES Astra’s direct-broadcast television presence in Britain and Ireland, plus small Ka-band payloads to provide broadband links among businesses, according to industry officials.

These three spacecraft, to be named Astra 2E, Astra 2F and Astra 2G and located at SES’s 28.2 degrees east slot, will feature about 15 kilowatts of power to their payloads and between two and four equivalent Ka-band transponders each.

It remains unclear what Luxembourg-based SES plans to do with the Ka-band. SES officials have long said they did not believe that the consumer satellite broadband market of the kind that has developed in the United States was big enough to justify investing in Ka-band. SES’s expanding Astra2Connect consumer broadband business uses Ku-band satellite links.

But in announcing its Astrium order Nov. 30, SES said the Ka-band “will allow SES to develop next-generation broadband services in Europe, including its growing Astra2Connect product.”

The fourth satellite, to be positioned at SES’s growing 31.5 degrees east orbital position, will have a smaller Ku-band payload and will include space for a navigation payload from the European Commission as part of Europe’s Egnos program to add a layer of reliability to the U.S. GPS constellation in lower-medium Earth orbit. The United States and Japan have similar GPS-overlay systems.

SES has already won an order to place a navigation payload on its Sirius 5 satellite, to be launched in 2011 into SES’s 5 degrees east slot. The company is hoping to win an order for a second GPS-overlay payload, operated in L-band, for the just-ordered Astrium satellite, to be called Astra 5B.

SES officials declined to comment on the payload configuration of the satellites and the reasons behind their choice of Astrium for what is the biggest single satellite order in SES’s history.

SES spokesman Markus Payer said the company believes that by ordering four spacecraft, it has saved more than 10 percent in what it would have paid had it ordered the spacecraft one by one, but less than the 20 percent savings SES said it realized in 2007 when it ordered two satellites, with an option for three more, from Orbital Sciences Corp. of Dulles, Va.

“These satellites carry a lot of on-board power and feature technology to switch beams from one satellite to another,” one industry official said. “When you add the constraints that SES habitually places on its contractors, you can easily get to a satellite that will cost 150 million euros or more. The contract may seem very expensive, but it’s in line with what SES could have expected and they certainly saved money over what they would have paid for the same satellites ordered separately.”

Early in the selection process, SES had eliminated all but two bids, with Astrium facing off against its principal European rival, Thales Alenia Space.

Industry officials had said Astrium was the favored bidder because Thales Alenia Space has less of a track record with SES than does Astrium in terms of current satellites in orbit.

The U.S. dollar’s recent weakness against the euro might have played in favor of a bid from one of the three U.S. contractors capable of building large, high-power television broadcast satellites — Boeing, Lockheed Martin and Space Systems/Loral. SES said it received bids from all the principal manufacturers.

One industry official said Lockheed Martin and Boeing continue to be only intermittent bidders for commercial satellite work, although both companies say they are looking at the commercial market with renewed interest.

Space Systems/Loral, this official said, has several satellites for SES either just launched or in production. SES would hesitate before ordering four more spacecraft from Loral to the extent that it would increase the satellite operator’s reliance on a single satellite platform.

SES officials also declined to comment on whether their decision to select Astrium was affected by the possible sale of SES’s ND Satcom ground-equipment company to Astrium Services, which like Astrium Satellites is 100 percent owned by Europe’s EADS aerospace company. Astrium Services and ND Satcom are already partners in a long-term contract to provide satellite gear and services to the German Defense Ministry. SES has been talking to prospective ND Satcom buyers in recent weeks but as of Dec. 4 had not announced a transaction.

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