National news agency, Australian Associated Press, will be shut down at the end of June with shareholders declaring its continued operation unviable.
The closure of Australia's AAP Newswire after 85 years has been described as a blow to democracy.
'The wire' has supplied articles to regional, national and global newspapers, broadcast outlets and digital editions in various forms since 1935 and on Tuesday, it was announced the business will make its final transmission on 26 June.
AAP is no longer viable in the face of increasing free online content, management said.
It means about 180 jobs will be lost from the company's editorial operation and hundreds more from subsidiaries.
Federal parliament acknowledged the move.
"You will leave a massive void in terms of information coverage," Opposition Leader Anthony Albanese told the chamber after naming each of the press gallery's AAP journalists.
"Democracy should not be taken for granted ... the Australian public will be less informed as a result of the decision today which is a great tragedy."
Labor MPs held up signs which read "thank you AAP" as Prime Minister Scott Morrison acknowledged the newswire's "proud history here in the Australian parliament".
"They have a wonderful history in this place and when you have such an important institution such as AAP coming to an end ... that is a matter of real concern."
Australian Associated Press' Pagemasters editorial production service - employing hundreds of people - will also close at the end of August.
AAP is owned by Nine, News Corp Australia, The West Australian and Australian Community Media.
AAP chairman Campbell Reid described the newswire as Australian "journalism's first responder".
"It is a great loss that professional and researched information provided by AAP is being substituted with the un-researched and often inaccurate information that masquerades as real news on the digital platforms," added Mr Reid, who is also a News Corp executive.
AAP provided reporting on general news, courts, politics, finance, entertainment, travel, racing and sport, sports results, plus images and video.
The decision to close had been tough but shareholders were left with little option, Mr Reid said.
"The number of organisations choosing to no longer rely on the AAP service has made the business unsustainable."
Editor-in-Chief Tony Gillies paid tribute to his team, describing them as "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," Mr Gillies said.
The Media, Entertainment and Arts Alliance described the closure as "a gross abandonment of responsibility by shareholders".
"AAP delivers news, photos and sub-editing services that the major media groups either cannot or will not," union president Marcus Strom said.
"Bean counters at the top of media organisations might think they can soldier on without AAP but the reality is it will leave a huge hole in news coverage."
The Alliance blamed the federal government's failure to effectively deal with digital content aggregators, search engines and social media, which has made news readily available for free online.
Federal Communications Minister Paul Fletcher said AAP's closure was a reflection of the wider media sector.
"Some types of content are struggling, other types of content are booming. Streaming services are booming," he told the ABC.
"Businesses in the media and communications sector are seeking to reposition themselves, building in areas that are growing and reallocate resources from other areas."