The BBC is facing a fresh threat of industrial action after announcing plans to axe 415 posts to save £48 million a year by 2016/17.
The cuts will be offset by around 195 new roles, meaning a net reduction of 220 jobs.
James Harding, the BBC's director of news and current affairs, gave details of the cuts to a staff meeting in London, saying: " Taking nearly £50 million out of a well-run organisation that provides high quality news services that are trusted, relied upon and used by millions of people is an extremely difficult undertaking.
"The challenge is how to make BBC News even better, despite having less money."
Michelle Stanistreet, general secretary of the National Union of Journalists (NUJ), attacked the announcement.
She said: "They plan to get rid of hundreds of staff - using licence fee=payers' money to cover the redundancy pay-outs - and then immediately hire in a load more. You couldn't make it up."
Gerry Morrissey, general secretary of the technicians' union Bectu, said he understood the posts would go before any of the new jobs were filled.
He warned of industrial action if the BBC went ahead with cutting the jobs first.
Journalists and technicians are already going on strike for 12 hours next Wednesday, to coincide with the opening ceremony of the Commonwealth Games, in a row over pay.
Mr Harding said: " We are living through a period of extraordinary change in news media. BBC News led the way first in radio, then in television and then online. Now, digital technologies offer us the opportunity to lead a fourth revolution in news.
"So, as well as setting out our savings plan this morning, we are also announcing proposals to restructure news and target investments in our future - in the digital transformation of BBC News, in our own original and distinctive journalism, in making this a better place to work.
"The BBC is one of the very best things about this country. It is trusted, needed and loved by the vast majority of people - and all they ask is that we keep on making it better. Delivering ever better value for money is part of that. Investing in getting and telling stories - in original, distinctive journalism - is part of that.
"And reorienting ourselves to lead the world of news into a digital future is part of that too."
Changes include reorganising the newsroom and programmes department into three operations, streamlining daily activity and back office efficiencies, integrating the World Service to reduce costs in international bureaux, back-office savings and changes to planning and commissioning.
The announcement also included proposals to increase sharing of production teams and international programming by the BBC News Channel and World News, combining the World Service and radio newsrooms and combining production teams for the World Tonight and Newshour programmes.
Plans were also announced to reduce the TV current affairs budget and a "reshaped" newsgathering operation, including smaller and more "agile" reporting teams.
The World Service budget will be increased by £5 million to £250 million by 2016/17.
The BBC said £12 million will be invested in digital platforms, and £8 million on creating additional specialist editors and correspondents.
In an email to staff, Mr Harding said: "I recognise that there is a difference between full-time positions and the number of people who fill them: given that we are an organisation where there is a high degree of job sharing and part-time working, I expect that closer to 500 people may be affected by these job closures.
"The redundancy process itself will mean pools of people are put at risk. I appreciate that this means an even larger number of people face uncertainty over the coming weeks. I would also stress that all of the changes are subject to consultation in the coming weeks.
"We will, as ever, make strenuous efforts to fill the new posts through redeployment, and we will welcome applications for voluntary redundancy. We cannot guarantee that we will always be able to grant requests but we will try to do so.
"We all share the distress, concern and anxiety that such a sweeping round of cost savings will cause. We are going to see colleagues that we respect leave the BBC. It will have an impact, directly and indirectly, on a great many people inside the organisation.
"We are going to go through a very testing time of uncertainty and change. Its consequences will be felt by audiences too: you cannot take tens of millions of pounds out of a news organisation that delivers so much to so many people every minute of the day and expect those losses to go unseen, unheard and unnoticed."
There will 79 post closures in the newsroom, saving more than £11 million, and around 53 cuts in newsgathering, saving £6.1 million.
The BBC added there will be two posts lost in political programmes amongst production staff, and 22 in p rogrammes for 2015/16, with a further five the following year.
Ms Stanistreet added: "These cuts will further undermine the ability of journalists to deliver quality content.
"The way in which the BBC wants to carry out the redundancies is the latest move from a management whose approach to recruitment is to grab a coffee with their pals and find them a berth without so much as an interview, doling out jobs with salaries that are way in excess of the normal rates."