The publisher of The Guardian and The Observer reported a pre-tax loss before exceptional items of £68.7m – more than four times the £14.7m loss it reported last year.
Last year it reported a total loss of £17.6m, or £19.1m on an underlying basis.
GMG’s pre-tax losses were also worsened by a £84m write-down in the value of its stake of Ascential, the magazine and events company.
It is also paying about £20m in restructuring costs of severance payments as the company cuts jobs.
Revenue for the year ending 3 April was down 3.8% to £209.5m.
Underlying earnings before interest, tax, depreciation and amortisation was a loss of £62.6m, a 61% decline.
Last week the publisher of the Daily Mail reported a 10% year-on-year fall in print ad revenue, with uncertainty over Brexit thought to be adding to the long-term challenges facing newspapers.
In January GMG’s chief executive, David Pemsel, announced plans to cut costs by 20% (about £50m) over the next three years. Pemsel’s plan is to break even at an EBITDA level by 2018/19.
Slower than expected digital ad sales have failed to offset a continued slump in revenue from print. Investment in The Guardian’s operations in the US and Australia has also increased costs.
During the year, The Guardian’s global online audience grew by 20.2% to 155 million unique monthly browsers in April.
Pemsel said: "Faced with a volatile advertising market, we have taken decisive action to control our cost base, reduce headcount, and grow our revenues around membership, branded content, video and data.
"We are on track to deliver a 20% reduction in our cost base over the next three years, while our unique ownership structure will allow us to continue to invest in the world-class journalism that these numbers clearly show our international audiences want."