The magazine publisher behind The Week and Country Life has warned of a deepening downturn as lower advertising revenues and a decline in reader numbers hit profits.

Future said its full-year performance will be at the bottom end of current market expectations as it reels from the impact of soaring costs and a darkening economic outlook.

The magazine group said digital advertising revenue and affiliate fees for promoting products had taken a tumble as a result of the challenging market conditions.

Future also suffered a fall in reader numbers across its portfolio of titles and warned this would continue into the second half of the year.

Pre-tax profit slumped 18pc to £66.4m in the six months to the end of March, while revenue fell 10pc to £404.7m.

Shares in Future dropped as much as 17pc, meaning the company is now worth just over £1bn, less than a quarter of its value two years ago.

The figures signal a tough start for new chief executive Jon Steinberg, who replaced long-serving boss Zillah Byng-Thorne last month.