Edward Snowden
© UnknownAmerican "Whistleblower" Edward Snowden
The sensation sparked by the revelations of ex-NSA employee Edward Snowden on the level of covert online monitoring by the U.S. online helped narrow losses at the publisher of the U.K.'s Guardian and Observer newspapers.

Guardian News & Media, which publishes the two newspapers and theguardian.com, reported a £30.6 million ($52.3 million) loss in earnings before interest, taxation, depreciation and amortization over the year to the end of March. This marked an uptick from the £33.8 million loss posted the previous year.

It's been quite a year for the media group, which won the highest accolade in U.S. journalism - the Pulitzer Prize - for its coverage of the NSA's surveillance activities, based on the leaks by Edward Snowden. After breaking the story, the Guardian worked together with The New York Times and ProPublica to report news from the leaked documents.

Neil Berkett, chairman of Guardian Media Group, which owns Guardian News & Media and reported a pretax loss of £26.1 million against a £43.9 million loss last year, said there was a shift underway as users increasingly moved to online media.

"The world is moving to a digital agenda -- the vast majority of our readers are purely digital," Berkett told CNBC on Tuesday. "There's a big shift in terms of users and the trick is to stay ahead of the game."

One way the Guardian is trying to do this is to focus on its digital strategy, he said. The group's digital revenue rose over 24 percent to £69.5 million over the year. Total group revenue rose from £196.8 million to £210.2 million.

The Guardian said its website clocked up 100 million monthly unique browsers for the first time in March this year, driven by strong international traffic. Online traffic from the U.S. grew 12 percent year-on-year, and Guardian Australia - launched in May 2013 - had garnered a "loyal following", the group said.

Berkett said he had seen "tremendous success" in the U.S. "America is an important part of what we're doing - over a quarter of our readers are now in the U.S.," he added.

Guardian Media Group is in the middle of a five-year transformation plan in an effort to reduce costs. In January, it announced that it would sell its 50.1 percent stake in Trader Media Group, the owner of publications including Auto Trader and AdTrader, to private equity firm Apax Partner.

"It was the right time (to sell), we achieved the right value and we will put those funds to good use," Berkett added.