Urgent talks have been requested with Aviva over its shock decision to relocate from Bishopbriggs.
East Dunbartonshire Council has contacted the company, a major employer in the area, seeking discussions over the surprise move and the implications for local workers as soon as possible.
There was no engagement with the Council - which has previously provided support to Aviva, alongside Scottish Enterprise - prior to the announcement.
The Council will also be seeking talks with the site owner over potential plans - in the event of Aviva leaving in summer 2021 - to populate the vacated business space.
Councillor Andrew Polson, Joint Council Leader, said, "This is bitterly disappointing news from Aviva - particularly as we were not consulted on any plans to move from East Dunbartonshire or even given prior warning.
"Officers could have helped Aviva to explore potential ways for the site in Bishopbriggs to remain open and perhaps expand. I am hopeful that - even now - that could still be a possibility.
"As a major employer in the area, this news will be a great shock to its workforce - already having to cope with the ongoing pandemic - and we are seeking clarity on what it will mean for local employees moving forward. It will also have a major impact on the local economy."
Councillor Vaughan Moody, Joint Council Leader, added, "It is most concerning that the Council was not consulted in advance over this shock decision by Aviva - a significant employer in East Dunbartonshire - to relocate out of the area.
"As a Council we provided support through our arms-length development company to enable Aviva to set up its Bishopbriggs premises and we have continued to work with the company, delivering public transport infrastructure and improved links to support its workforce.
"The move will affect many local residents who currently work at Aviva, and may also have an impact on public transport provision and other local businesses, as well as the wider economy."