British satellite company Inmarsat said its core shipping business would gradually return to growth after it posted a 23 percent rise in full-year core earnings, broadly in line with expectations.

Inmarsat has suffered a slowdown in revenue from shipping as users switch to its next-generation broadband terminals. Sailors use the machine to send email and update facebook rather than making more lucrative voice calls.

Chief Executive Rupert Pearce said he expected the revenue growth trend in its core maritime business to improve in 2012.

The company said revenue in the unit from 2012 to 2013 would be between zero and 2 percent, but during 2014 to 2016, when it introduces its new Global Xpress service, it expects growth to accelerate to between 8 percent and 12 percent.

Inmarsat posted core earnings of $854 million (539 million pounds) on total revenue up 20 percent to $1.41 billion, both broadly in line with market expectations.

The British company's revenues from a spectrum sharing agreement have also dried up as its cash-strapped partner LightSquared defaulted on a payment last month.

LightSquared's plans to build a new network in the United States suffered a major blow when the Federal Communications Commission said it would bar the service.

Inmarsat said on Tuesday it was in discussions with LightSquared but it was not sure it would receive any outstanding payments, nor any further payments.

It is paying a final dividend of 24.96 cents, up 10 percent.

(Reporting by Paul Sandle)