Around 450 jobs will be cut from BBC News under plans to complete its £80m savings target by 2022.
Outlets to be hit by job closures include BBC Two's Newsnight, BBC Radio 5 Live and the World Update programme on the World Service.
BBC News boss Fran Unsworth said there had to be a move away from traditional broadcasting and towards digital.
But broadcasting union Bectu said the changes mean staff will be "under even more pressure to deliver".
The job cuts announced on Wednesday include the previously announced closure of BBC Two's Victoria Derbyshire programme.
BBC News currently employs around 6,000 people, including 1,700 outside the UK. Its budget after the changes will be around £480m per year.
Unsworth, who is director of BBC News, said: "The BBC has to face up to the changing way audiences are using us.
"We need to reshape BBC News for the next decade in a way which saves substantial amounts of money. We are spending too much of our resources on traditional linear broadcasting and not enough on digital."
What will be cut?
The corporation announced in 2016 that it needed to save £800m, with around £80m of that figure coming from News.
Just over £40m - around half - of the savings required in BBC News have already been found over the past four years.
The remaining savings will be found in large part by restructuring the newsroom to adopt a "story-led" model, which will see planned stories each rolled out across a greater number of programmes and outlets.
The BBC said this would avoid the duplication that occurs from several programmes putting resources into the same news stories.
However, the changes mean there will be a reduction in the overall number of stories covered, and Newsnight will produce fewer films.
The corporation said further information about which specific jobs are to go will be announced early in the summer.
Unsworth also said there would be a review of the number of presenters BBC News has and how they work.
While Victoria Derbyshire and World Update will be closed, Unsworth said there are unlikely to be any further closures of entire programmes or services.
The savings are expected to result in post closures across BBC News as the planning and commissioning of stories is centralised.
The BBC News website will be largely, although not entirely, protected, as the corporation prepares to invest further in digital, including the launch of a new version of the BBC News app.
The 450 job cuts include around 50 post closures at the World Service that were announced at the end of 2019.
The BBC announced in 2016 it needed to save £800m by 2020; BBC News was to provide £80m of those savings, and it is only half way.
The BBC is struggling to connect with many British people - especially those from poorer socio-economic backgrounds, and - even more so - those under 35.
The licence fee, which accounts for around 75% of the BBC's revenue, is under unprecedented political and structural pressure.
These three facts have driven the changes announced today.
The first made pain inevitable; the second has determined the nature of the cuts announced; the third means the audience the BBC has in mind when making these changes isn't just licence fee payers - it's the inhabitants of 10 Downing Street.
Writing on Twitter after the latest announcement, Victoria Derbyshire took issue with the reasons behind the decision to close her programme.
"We were NEVER asked to grow the linear TV audience. Ever," she tweeted in response to a journalist who suggested the viewing figures for her programme were low.
"We were asked to grow our digital audience - we did," she said.
Michelle Stanistreet, general secretary of the National Union of Journalists, responded to the announcement by saying: "These damaging cuts are part of an existential threat to the BBC, and a direct consequence of the last disastrous, secret licence fee deal the BBC agreed with the government."
Bectu national secretary Noel McClean said: "The unprecedented constraints faced by the BBC will leave our members under even more pressure to deliver the output and service that has made this essential public service the envy of the international broadcasting community and risks its future viability."
Damian Collins MP, who is standing for re-election as chair of the House of Commons culture select committee, said there would be "concerns" about the plans.
"They should explain how it'll impact the BBC's ability to reach people," he wrote on Twitter.
TalkRadio host Julia Hartley Brewer and former Newsnight economics editor Paul Mason were among those offering their views on the plans on Twitter.
My sympathies go to every BBC journalist who faces losing their job today and I wish them the best in finding new work. But, as a taxpayer-funded organisation, the absurd over-staffing at the BBC simply cannot be justified anymore. There is no reason for BBC output to suffer.— Julia Hartley-Brewer (@JuliaHB1) January 29, 2020
THREAD (dedicated to my ex-colleagues at NBH).... What's wrong with Fran Unsworth's vision for BBC News: 1) Any editorial graphic where "original journalism" is in the bottom corner is a recipe for News becoming an announcement board for business, the monarchy and the state... pic.twitter.com/Bx8COENog5— Paul Mason (@paulmasonnews) January 29, 2020
Meanwhile, the BBC has suspended the closure of its Red Button text service after protests, a day before it was due to have started being phased out.
On Monday, a petition calling for it to be saved, organised by the National Federation of the Blind of the UK (NFBUK), was handed in to the BBC and Downing Street.