Satellite firm Inmarsat warned on a challenging market and an unpredictable outlook today, sending shares sliding almost four per cent.
The firm posted half-year revenue growth of 7.7 per cent to $356.0m (£270.8m) but earnings fell by 3.6 per cent to $195m.
However, Inmarsat said it was on track to meet its full-year revenue targets.
In a statement, the FTSE 250 group said: "We remain confident about the medium to long term outlook for Inmarsat. However, whilst we have delivered a robust performance in recent quarters, our markets remain challenging and the outlook continues to be difficult to predict."
Chief executive Rupert Pearce said: "Our robust performance in the first half of 2017 validates Inmarsat's powerful position as the leading operator in global mobility markets, our operational and commercial strength, the uniqueness of our connectivity offerings and our continued success in commercialising our technology to service the requirements of our customers.
"We will continue to build on these strong foundations, supported by further investment into our organisational capabilities.