The latest figures from the Audit Bureau of Circulation showed falling February sales for the Guardian, Times and Independent. Hardest hit were the Guardian and the Times, which recorded respective 16.4 per cent and 16.9 per cent declines in year-on-year sales.
The Guardian's average daily circulation also fell below 300,000 for the first time in 30 years.
The slump reflects the impact of cuts in the paper's foreign distribution, as well as the end of bulk distribution in August last year.
The Times now sells a daily average of 505,062 copies. However, despite its year-on-year losses, this figure represented a fall of less than 1 per cent from January, when the paper ceased to count bulk distribution figures.
The Independent's average daily sales for February sank to 183,547 copies, a 10.88 per cent fall on last year.