Tech firm currently employs 150 people in the town
US technology company eBay is to close its operations in Dundalk in the second quarter of next year.
In an email sent to staff today, Senior Vice-President of Global Customer Experience Steve Boehm said the company is proposing to expand in the operating locations where it already owns or leases space.
"We confirm that PayPal has served us notice as tenants of their Dundalk facility," eBay said in a statement.
"We will begin a formal consultation process with our colleagues in Dundalk and will share any further information with them as a matter of priority," added the firm, which employs 150 people in the town.
Minister for Jobs Mary Mitchell-O’Connor said she "very much" regretted eBay's decision.
"The company’s employees there have played a key role in its success over the last number of years which makes it particularly disappointing that eBay have decided to leave Co Louth," she said.
Ms O'Connor added: "It is difficult to speak about positives at a time when workers have just discovered they may soon lose their jobs.
"But it is the case that eBay’s employees are highly-skilled and working in the IT sector which is continuing to expand rapidly.
"I am also very hopeful that other companies expanding in the border region will employ many of those who may be affected by eBay’s decision.
"I want to stress as well that eBay have made it clear that today’s announcement has no bearing on their site and employees in Blanchardstown."
The minister said she has met with the IDA this afternoon to discuss today’s announcement.
Sinn Féin TD for Louth Gerry Adams described the closure as "dreadful news" for eBay workers and their families.
"I have spoken to the Minister for Jobs, Mary Mitchell O'Connor today and I encouraged her and her Department to engage with the workers to ensure that they are fairly treated," he said.
Paddy Malone from the local Chamber of Commerce also expressed his disappointment.
"Given what has happened with Brexit over the last two months, I'm disappointed that the government didn't do more to keep eBay in Dundalk," he told the Dundalk Democrat.
"It's bad enough with Brexit looming over the town without this. This is just a body blow to the town.
"I hope that Paypal might be in a position to offer some of those people jobs, so that we could hold on to some of them."
PayPal became the landlords of the current facility in Dundalk when it separated from eBay last year. The company has now informed eBay that it intends to expand its own facilities on the site.