Economy, Tourism and Transport Secretary Stephen Flynn said the redundancy scheme was part of efforts to modernise the shipyard and put it on a more competitive footing.
“The action that the leadership team at Ferguson Marine is taking today is necessary to help secure a viable future for the yard, and that of commercial shipbuilding on the Clyde,” he said.
Flynn said he had been assured that the reduced workforce would not affect the building of the MV Glen Rosa.
And he added: “Our intention to directly award four vessels continues to undergo full due diligence further to next steps which will be announced to parliament in due course.”
Louise Gilmour, Scotland secretary of the GMB union, said ministers had failed to deliver new contracts while sending work around the world.
“Fergusons was once Scotland’s ferry factory with a worldwide reputation for excellence and should be again,” she said.
“Instead, skilled and experienced shipbuilders are being encouraged to leave as those in charge send contracts everywhere but here.”
She said the “hubris and incompetence” of those in charge of Scotland’s ferry network had “failed a blameless workforce that deserves the chance to turn the page”.
Local Labour MP Martin McCluskey said the news was “deeply concerning” and part of a “jobs crisis” in Inverclyde.
“The Scottish government needs to step up, move faster and do everything within its power to secure the future of Ferguson Marine and the skilled jobs that depend on it,” he said.