Shares in the newspaper publisher Johnston Press plc (LON:JPR) fell as much as 21 percent after posting a drop in revenue.

Owner of the Yorkshire Post and Scotsman reported a ten percent fall in revenue in the first half of 2018 following changes to Google’s online search algorithm and Facebook feed.

Revenue fell from £103.3 million in 2017 to £93 million to the first six months of 2018.

The group, which owns about 200 titles across the UK, reported a growth in pre-tax profit of £6.2 million compared with a loss of £10.2 million the same period a year previously thanks to strong sales of the “i” national paper.

“The continued challenges posed by Google and Facebook, seen most recently through algorithm and news feed changes, have contributed to total digital revenue decline, while balance sheet constraints have restricted the group’s ability to invest and counter these effects,” said David King, the new chief executive of Johnston Press.

“As part of the strategic review, the group continues to explore its options for the refinancing or restructuring of the group’s debt but, as yet, no decisions have been made nor agreements reached.”

King said that the sales of the “i” newspaper “demonstrated that it is possible to grow a newspaper brand, despite the prevailing headwinds”.

Shares in the group (LON: JPR) are currently trading down 18.04 percent at 4,18 (1333GMT).