Dublin-based travel business CarTrawler has signed up to a partnership with Spain's national rail provider Renfe.
The deal will provide Renfe passengers with direct online access to the company's portfolio of more than 1,500 car rental agencies.
Michael Cunningham, chief commercial officer of CarTrawler, said the deal would take customers' travel experience "to the next level".
Renfe runs more than 5,000 trains daily and moved more than 465 million passengers in 2015.
The partnership follows the Dublin business signing up to a similar agreement with Shannon Airport earlier this month, which Cunningham described as the "first of its kind in Ireland".
At the time, Isabel Harrison, B2B manager of Shannon Airport, said: "By becoming the first Irish airport to work with CarTrawler we are yet again leading the way in offering our passengers a value proposition.
"Our aim is to make FlyShannon.ie a one-stop-shop for all our passengers' needs. So, not only can you plan and book your holiday through FlyShannon.ie, you can now book your airport transfer or car hire at your final destination, safe in the knowledge that it will be waiting for you when you arrive."
