A total of 300 jobs will be lost nationwide following announcements by the firms FBD and Element Six.
Insurance company FBD is to close 13 of its offices nationwide with the loss of 150 jobs.
The company says it hopes to achieve the staff reductions through voluntary redundancies.
It is to cut its offices from 47 to 34 by merging the activities of certain offices.
An FBD spokesperson said it has 953 full-time positions and it is envisaged that after the voluntary redundancies it will have 800 full-time positions.
160 people work at a support centre in Mullingar, Co Westmeath, which opened in February 2007.
The insurance firm said it decided to close the offices after a detailed review undertaken by the company in recent months.
150 jobs to be lost in Shannon
This review was initiated as a result of major changes in the way customers are buying insurance, with over 70% of car and home insurance customers now using the telephone or Internet.
The company said it was entering a consultative process with staff and representative bodies immediately.
Separately, Shannon-based company Element Six Ltd has informed its staff that the company intends to reduce its workforce by 150 before the end of the year.
The company currently employs 620 people in the manufacture and distribution of industrial diamonds and super-hard materials.
The company claims that these job reductions are part of a group-wide cost-saving programme, not just in Ireland but across the world.
General Manager of the Shannon site Ken Sullivan said: ‘Our major customers include those in construction, automotive, general engineering and the drilling for oil and gas.
‘All of these are caught up in the down turn in global business. In some sectors, sales are running as low as 50% of what we would have expected a few weeks ago.’
The company will immediately be entering discussions with the employees and their representatives.
Element Six is the world's largest manufacturer of industrial diamond and has plants in South Africa, Sweden, Isle of Man, UK, China and the Ukraine.
