The AAP newswire service is to close by the end of June, after 85 years of supplying news stories to newspapers, broadcasters and digital outlets.
Chief executive Bruce Davidson has confirmed that more than 180 staff spread across Australia, Los Angeles and London will lose their jobs, including about 30-40 moderators and journalists in New Zealand.
Davidson told staff today the business was "no longer viable in the face of increasing free online content".
AAP - which was founded by Keith Murdoch in 1935 - will cease operations at the end of June.
The company's Pagemasters editorial production service, which has been operating for 29 years, will also close at the end of August, while its Medianet and Mediaverse businesses will be sold off.
AAP is owned by Nine, News Corp Australia, The West Australian and Australian Community Media.
In a message to staff, Davidson said the decision meant there would be job losses, but "there will be employment opportunities as our shareholders and other external companies reorganise the way they receive news and page production services".
"In particular, News Corp and Nine will be making additional investment in their own news teams to replace some of the content they currently source from AAP.
"This decision does not reflect on the quality, trust, accuracy and reliability of the AAP news service, but rather an economic reality."
AAP chairman Campbell Reid said it was a "great loss" that AAP's copy was "being substituted with the un-researched and often inaccurate information that masquerades as real news on the digital platforms".
Editor-in-chief Tony Gillies said the AAP team were "the most humble and hardest news people".
"We have had a place like no other in journalism. We exist for the public's interest and I now fear for the void left by the absence of AAP's strong, well-considered voice."