Negotiations are starting with employees with a view to a final decision being reached by the end of July.
The cost-savings programme, originally announced by Metsä Wood in Finland in April, will involve up to 150 jobs losses in the UK out of a possible 255 jobs losses across the company.
"Metsä Wood is proposing to reallocate elements of its operations between its Grangemouth and Boston units," it said.
"This could result in a possible reduction of up to 45 jobs at the Grangemouth site and a possible reduction of up to 30 jobs at the Boston site.
"Grangemouth would remain a key distribution hub with specialist operational activities in order to maintain the levels of service and existing product portfolio for Scotland and the north."
The cost-savings programme, which involves a detailed review of all Metsä Wood UK’s timber and upgrades business line operations, is designed to ensure future competitiveness and profitability.
The company recently lost a major timber supply contract with DIY retailer Wickes.
Metsä Wood UK has five sites – its head office at Basildon, Boston, Grangemouth, Widnes and King’s Lynn, where the Finnjoist I-joist product is manufactured.
The UK I-joist and pole processing businesses have been identified as "non-core" and are being subjected to strategic analysis as part of the review.
