Ministers 'focused on future-proofing' Grangemouth amid fears over jobs
However, it is suffering annual losses stretching into the tens of millions, with restructuring advisers reportedly set to be brought in by its Chinese backers.
The site is part-owned by Beijing state energy firm PetroChina, which bought a 50 per cent stake from Sir Jim Ratcliffe's Ineos Group in 2011.
SNP environment minister Mairi McAllan insisted it was an "exceptionally important" site and a "major source of highly-skilled manufacturing jobs".
However, she said it would not be appropriate to comment on "media speculation".
Ms McAllan was asked about reports by Tory MSP Tess White, who said Grangemouth was "one of the most strategically important employers in Scotland, with hundreds of staff across the site".
She said: "They will understandably be alarmed at the prospect of restructuring at the refinery."
Ms White said Grangemouth accounts for 4 per cent of Scottish GDP and 8 per cent of Scotland's manufacturing, supplying two-thirds of petrol and diesel in Scotland as well as jet fuel for airports.
She said: "A change in outlook for the refinery's future has wide-ranging and wide-reaching repercussions."
Green MSP Gillian Mackay said: “I grew up in Grangemouth and know how important a just transition will be for workers, the planet and the communities that surround the Grangemouth refinery.
"The community needs the Scottish Government to do everything it can to deliver a just transition."
Ms McAllan told MSPs: "Future-proofing this vital industrial hub and working in partnership with industry is our objective and will help to support a long-term, sustainable and vibrant future for Grangemouth, for all those who live and work there."
A Scottish Government spokeswoman previously said: "Grangemouth is a source of critical infrastructure, energy resilience, skilled manufacturing and high value employment.
"In recognition of this – and the important role the complex will play in our net zero economy – we recently established the Grangemouth future industry board, with the planning for a just transition to net zero at the heart of the board's work."
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