The National Trust for Scotland has been warned it risks "damage to its long-term aims" with plans that could see up to 139 staff made redundant.
The trust wants to reduce costs by 10% and "simplify" its management structure.
It said it had "a bold and ambitious vision to change the way we deliver our core purposes".
But the Prospect union said possible redundancies would be a "devastating blow to Scotland's heritage sector".
BBC: Union warns over National Trust for Scotland job losses
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