Details of a proposed £40 million cement factory at Killaskillen near Clonard, Co Meath, have been announced by the Belfast-based Lagan Group.
Some 200 permanent jobs are due be provided by the plant, which aims to be fully operational within two years of planning approval. A further 100 jobs would be created in the 12-month construction period.
The proposed factory, called Lansdown, will produce white cement which, made from high-grade limestone, is used in specialist work and is more costly than normal grey cement.
Mr Kevin Lagan, chairman of the group, said the plant should manufacture up to 500,000 tonnes annually at full production, at least 200,000 tonnes of which will go each year towards substituting white cement imported by the company.
He said initially the company's main export markets will be the east coast of the US and Mediterranean Europe, where demand for white cement is greater because of the climate. Grey cement tends to stain and discolour under excessive heat.
At present, Denmark is the only northern European country with a white cement manufacturing plant.
The Lagan Group is also examining potential opportunities in Britain and Ireland, where white cement is used in marble works. In addition, a research and development unit at the plant will look at whether the cement could be used in the manufacture of such products as animal feed, toothpaste and plastic.
Mr Lagan said the 500-acre site was chosen because of the "unique" quality of its limestone. Two other sites in the area had been purchased and drilled before it was discovered.
The plant will include a 100-acre quarry, a cement works and stockpile area. It is expected to have a life-span of about 50 years after which the area will be restored. Mr Lagan said the company wished "to work closely with the local community". A planning application and environmental impact statement will be lodged shortly with Meath County Council. An information centre will be established at Lansdown to facilitate people from the local area who wish to view the plans.