IDA Ireland says several companies have contacted it about taking over the Fruit of the Loom factories in Co Donegal which are set to close.
However, the agency declined to name them and said it might take several months before a replacement industry was found.
A large call centre is the most likely replacement, but the healthcare sector was also being targeted, an IDA spokesman said.
The agency says lack of infrastructure in Co Donegal remains a stumbling block, but the low age profile of the workforce and the quality of the three plants which will become available are significant advantages in the search for replacements.
However, the IDA has already warned the Tanaiste, Ms Harney, that it is difficult to attract industry to Co Donegal because of access, the Northern troubles and the low population density.
Mr Michael McCloone, chairman of the Donegal Taskforce, said yesterday he was confident replacement industries could be found. However, he said its first job would be to assess the skills profile of the workforce.
The taskforce will interview every Fruit of the Loom worker who has been made redundant to assess their skills.
"If they want to be retrained we will accommodate that. If they want to stay in the textile and clothing area we will try to do that," Mr McCloone added.
The chief executive of the IDA, Mr Kieran McGowan, said the agency's concentration on development "will be broader than in the Inishowen peninsula".