The Guardian has confirmed losses of £69m for the last financial year but said it was making significant progress in its membership scheme, with more than 50,000 people paying to sign up.

Membership is a core part of plans by the publisher’s parent company, Guardian Media Group, to counteract falls in both print and digital revenue, which led to an £8m fall in total turnover to £209.5m.

The industry as a whole has faced greater than expected declines in print advertising over the past year, while digital ad growth has almost all gone to Google and Facebook.

Not including one-off costs, the revenue decline resulted in a pre-tax loss of £68.7m, compared with £14.7m in the preceding year. On an underlying basis, losses were £62.6m, up from £38.8m.

However, exceptional items totalling more than £104m, including an £84m writedown of the value of its stake in business publisher Ascential, meant the company recorded a total loss of £173m.

Guardian Media Group chief executive David Pemsel and Guardian News & Media editor-in-chief Katharine Viner have introduced a strategy aimed at cutting costs by 20% over the next three years and developing new sources of income to counteract falling print ad revenues and volatility in the digital ad market.

The company has just cut more than 260 jobs through a voluntary redundancy programme that will save £17m a year, but Pemsel said management would continue to monitor performance on a quarterly basis.

He said: “Every quarter we will look at that, and if that gap starts to widen again, it is inevitable that we will have to look at costs again. But we are a private company, we do still have the money in the bank, we still have an incredibly supportive board and an amazing trust, and they don’t want us to cut our way to success.”

Digital revenues were £81.9m, down almost £2m from from the preceding year as Facebook and Google ate up the bulk of the money made from mobile advertising. Weak revenues in the UK were partly offset by growth in the US and Australia.

Pemsel said he expected digital advertising to improve over the current financial year, as the Guardian moves away from selling advertising based primarily on the scale of its audience to use more data and behavioural information. The company is also continuing to develop its Guardian Labs division, which creates sponsored and branded content for advertisers.

However, he said print advertising – which was down by 15% year on year – would continue to fall across the industry.

The membership scheme is a core part of the Guardian’s plan to more than double revenue generated from readers from £30m to £68m within three years. Members pay between £5 and £60 a month to join one of three tiers of membership, receiving benefits including priority booking and discounts for events.

Growth has accelerated in recent months, driven by new strategies and the Guardian’s coverage of big stories, including the Panama Papers and the UK’s vote to leave the EU.

The Guardian also has a further 150,000 people signed up as non-paying digital members and a total of 181,000 subscribers across print and digital.

Pemsel said the membership scheme was still in its early days and the Guardian was trying a range of methods to encourage people to sign up. He would not rule out making some forms of content available only to members, but said there were no plans to launch a paywall and the membership model would not try to force people to pay.

He said: “What we’ve got to work out, is it a donation, someone just saying I want to keep the Guardian open and free to all? Is it in exchange for value – you give us a bit more and it’s a bit more personalised? Actually the banner of membership could be a whole number of different iterations about how we build deeper relationships with our readers and get them to make a greater contribution.”

The Guardian retains cash and investments of £765m, down from £838.3m last year, and its stake in Ascential was worth £206m in April following the writedown.

Pemsel added: “We want to deliver on membership, we want Labs to succeed, we want America to hit its numbers. If all those things work and we focus and become much more committed to addressing our cost base ... we will be fine.”