The Sun has been behind a paywall since August 2013. In November 2014, News UK reported it had signed 225,000 subscribers to its £2-a-week digital service Sun+.
In an internal email today, Mike Darcey, chief executive of News UK, said the move was a chance to "strengthen our mission to secure a sustainable future for our journalism".
Plans to evolve The Sun’s business model into something more nuanced are said to have been a year in the making.
Darcey said: "From early July, select digital content from The Sun will be available for free.
"Much of this content will be generated on a bespoke basis by new teams, but editors will also be able to deploy other Sun stories, especially ones well covered by competitors. Expect to see early moves of this kind in the areas of general news and sports."
Interestingly, Darcey goes on to explain News UK will attempt to decide what content becomes openly available based on "shareability" via social media.
Noting the continued rise of social media as a way people are now reading news, the chief executive said: "By doing so, we can extend the reach of The Sun brand, bring more people into a Sun conversation and provide an entry point to our paid propositions, both print and digital.
"At the same time, we will be expanding our pool of digital inventory, making us better placed to respond to the calls of advertisers for solutions across print and digital."
The move signals a marked step-change from News Corp's chairman Rupert Murdoch’s stand against giving away the "expensive commodity" of content online for free.
Unlike News UK’s website for The Times, which became the first British national paper to erect a paywall in the summer of 2010, The Sun has struggled to lock in readers via its membership scheme.
Darcey today stressed this was "the beginning, not the end", of The Sun’s evolution, and it follows the launch of its free political website Sun Nation ahead of this year’s General Election.
He said: "We are pursuing this opportunity in a way that continues to protect the paid-for edition in print and tablet form, which funds our journalism.
"In turn that means we need to be true to The Sun brand, while also ensuring that our free digital presence is differentiated from, and does not diminish the value of, the paid edition.
"We will engage with social media, while avoiding becoming merely a news feed for other aggregator brands. And we will gain much experience in how best to tell stories in the digital world.
"We will also make sure that we execute this shift in a way that provides a net positive contribution to profitability."
As the fifth anniversary of its paywall approaches, The Times is reported to be making a profit for the first time in recent history.