PARIS — Satellite-bandwidth retailer London Satellite Exchange and mobile satellite services provider Stratos Global Corp. are teaming to provide mobile satellite communication services to European defense forces in anticipation of a new product line offered by the Inmarsat-4 satellites.

LSE and Stratos say the Broadband Global Area Network (BGAN) high-speed mobile communications service provided by the two Inmarsat-4 satellites — a third satellite is scheduled for launch by early 2008 — is being adapted in 2007 in ways that should broaden its appeal to military users.

As is the case with most sellers of Inmarsat services, Bethesda, Md.-based Stratos derives a substantial portion of its revenues from military customers. In 2006 Stratos joined forces with LSE to provide services to the French military. LSE and its majority shareholder, Astrium Services, already are supplying satellite services in the C- and Ku-bands to the French navy and for communications with unmanned aerial vehicles.

LSE President Dylan Browne and Stratos Vice President Ian Canning said they expect sales of BGAN service to French and other nations’ military forces to increase sharply in 2007 as the BGAN service is broadened to aeronautical and maritime users.

LSE, Stratos and London-based Inmarsat outlined the new services here Feb. 7 to French industry and military officials.

BGAN, which provides two-way communications at speeds of up to 492 kilobits per second, was introduced in late 2005 for land-mobile applications using laptop-size terminals.

BGAN is made possible by the two Inmarsat-4 satellites currently in a geostationary orbit that provides coverage of the Atlantic and Indian ocean regions. The third Inmarsat-4 satellite, whose construction is complete, is expected to be launched by early 2008 into a Pacific Ocean slot, which will make BGAN coverage nearly global, except for the North and South poles.

LSE Vice President Nat Chabert said that for multinational coalitions, Inmarsat is sometimes the only transmission standard that is fully interoperable among all coalition partners.

Military customers and members of the broadcast media — also heavy users of Inmarsat — have raised concerns that each of the Inmarsat-4 satellites’ 200 spot beams can handle only a limited number of simultaneous users.

With each spot beam measuring some 800 kilometers in diameter, this means Iraqi coalition forces and media customers will quickly run up against the limits of the spot beam over the Baghdad region, for example — unless individual customers elect to reserve capacity in advance, which can be expensive.

Gordon McMillan, director of government services at Inmarsat, said that for now, many of the Inmarsat-4 satellite’s spot beams over ocean regions are not in use, and this capacity can be redirected over Iraq or other regions where demand is heavy.

How long that solution will work is unclear. Stratos and other Inmarsat service providers this year will begin offering BGAN for aeronautical and maritime use as part of services retailed under the name SwiftBroadband and FleetBroadband, respectively.

Once these new services are in place, it will be more difficult for Inmarsat to move beams around without interrupting services for customers in lower-use areas.

For military users, the arrival of the aeronautical and maritime BGAN services will give them the ability to use a single BGAN subscription to move from one satellite spot beam to another — a feature currently not available.

The new aeronautical and maritime BGAN services also will benefit subscribers with mobile equipment for land-based operations. Inmarsat and Stratos, for example, already have field-tested BGAN terminals aboard Humvees and other land-mobile vehicles with an antenna designed to remain oriented toward the satellite as the vehicle moves.

McMillan said the ability of Inmarsat to transfer calls from one spot beam to another will be introduced this year.

Stratos and LSE also are offering military customers the possibility of hiding their exact whereabouts within a given spot beam through an option that switches off the GPS locator on each BGAN terminal.

While this feature, which means the signal location cannot be determined except to confirm it is within a certain spot beam’s 800-kilometer-wide coverage, has appealed to some military forces, others are wary of it.

“When we show this to some customers in the military, they say they don’t want it because they don’t want their signal to look different in any way from the commercial signals being sent to the satellite,” Canning said. “Their message to us is that they want to blend in with the overall traffic in every way.”