PARIS — Mobile satellite services operator Inmarsat said Nov. 2 it likely will report zero growth in its core business in 2011 but that cash coming in from a struggling wireless-broadband startup in the United States will nonetheless give the company a record-breaking year in both revenue and profit.

London-based Inmarsat said its hand-held satellite telephone, which has been on the market since mid-2010, has been taking at least 10 percent of the market for new satellite telephone subscribers and, in that respect, is meeting company forecasts.

But usage and revenue from the IsatPhone have “developed more slowly than anticipated,” Inmarsat said in a Nov. 2 document filed with the London Stock Exchange.

In a Nov. 2 conference call with investors, Inmarsat Chief Executive Andrew Sukawaty said the company is beginning to win over business formerly devoted to the higher-priced handsets offered by Iridium Communications of McLean, Va.

Customers in Inmarsat’s core maritime and aviation markets are in the midst of a product change-out that will allow them get the same amount of communications throughput for less monthly cost. Aided by Inmarsat incentives, the FleetBroadband maritime product has been successful beyond Inmarsat’s forecasts.

Some 23,500 ships worldwide have adopted FleetBroadband — 10,000 in 2010 alone and around 7,500 for the first nine months of 2011.

Inmarsat is counting on customers gradually increasing their bandwidth usage and returning to previous monthly subscription payments, and eventually surpassing those spending levels as they become accustomed to using broadband.

But that spending growth will take time. For now, maritime revenue is decreasing slightly. Inmarsat has said this trend likely will reverse in 2012, although the company is not yet forecasting specific growth for next year.

Providing broadband links to maritime vessels and offshore energy platforms is a focus of satellite operators that until recently were not competing directly with Inmarsat. With the decrease in price of very small aperture terminal (VSAT) hardware, Inmarsat is seeing some of its heavier users adopt Ku-band services, which are less expensive, when measured in delivered bandwidth, than Inmarsat’s L-band services.

To counter this, Inmarsat is investing $1.2 billion in a next-generation, Ka-band service called Global Xpress. The Global Xpress satellites are scheduled for launch starting in 2013, and will offer up to 50 megabits per second of bandwidth to ships with 60-centimeter Ka-band antennas.

Inmarsat in April spent $113 million to purchase Ship Equip of Norway, which has installed Ku-band VSAT gear on about 1,000 ships, as a way of guiding VSAT customers toward Global Xpress. This summer Inmarsat introduced Xpress Link, which is typically a five-year contract with ship owners that offers Ku-band VSAT service, plus Inmarsat’s FleetBroadband L-band service, in exchange for a commitment from the ship owner to convert to Global Xpress when that is available.

Inmarsat estimates that Ku-band VSAT gear has been installed on around 6,000 maritime platforms, including between 4,500 and 5,000 merchant ships that are at the heart of Inmarsat’s market.

In a Nov. 2 interview, Sukawaty said that VSAT installations had been running at 1,000-1,500 ships per year in the last couple of years but have slowed to perhaps half that number in 2011.

In the conference call, Sukawaty said Ku-band VSAT providers in the maritime market often advertise huge coverage areas that, on examination, are much smaller — and offer much slower connections — than expected. This is because these companies must stitch together Ku-band coverage from several satellites whose main focus is land areas.

“You really have to look closely at these coverage maps,” Sukawaty said. “What you find is that they are offering 64 kilobits per second with very limited coverage. Our guys have joked that VSAT actually means ‘very slow actual throughput.’ That is not going to put any dents in us.”

Inmarsat’s anticipated record revenue growth in 2011 is almost entirely due to cash payments from LightSquared of Reston, Va., a startup company developing a satellite-terrestrial wireless broadband network in the United States. To secure a sufficiently large swath of L-band spectrum to provide its service, LightSquared has agreed to pay Inmarsat to modify Inmarsat’s use of the same spectrum and, where needed, to retrofit Inmarsat customers’ hardware so as not to interfere with LightSquared.

LightSquared has yet to receive final operating approval from the U.S. Federal Communications Commission (FCC). Whether LightSquared will receive a license this year given the controversy over its system’s potential interference to GPS positioning, navigation and timing satellite signals is unclear.

Inmarsat had received $420.6 million from LightSquared as of Sept. 30, $268.1 million since the beginning of the year. Inmarsat expects to recognize $152.8 million of that revenue this year. These funds will more than make up for the weakness in the mobile satellite services market.

Sukawaty made clear that Inmarsat expects LightSquared to work through its GPS-related issues and to receive an FCC license. But whatever LightSquared’s future, he said Inmarsat will not be returning any cash.

“There is no cash claw-back at all,” Sukawaty said when asked if a LightSquared collapse would force Inmarsat to return any funds. “Whatever cash we’ve received, we keep.”

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