Union leaders are considering legal action against Pilkington, claiming the company failed to consult with its workers before agreeing to a £2.2bn takeover by Nippon Sheet Glass.
Yesterday, the St Helens-based firm confirmed that its directors had accepted the Japanese firm's offer of 165p a share after months of negotiations.
Early indications suggested there would be no threat to jobs at Pilkington's site in the town once the deal, which is subject to shareholder approval, went through.
St Helens North Labour MP Dave Watts and St Helens Council both gave a cautious welcome to the news, adding they hoped the Pilkington name would remain.
However, Ronnie Waugh from the GMB Union, which represents workers at the company, claimed workers had not been consulted.