The campaign will encompass voucher codes, API, email marketing, text links, verticals, comparison sites and cashbacks.
It will cover UK, Germany, France, Switzerland, Austria, Italy, the Netherlands, Portugal as well as the 400-strong hotel group’s home market of Spain.
The move comes as NH Hoteles has 20 new hotels under construction which will add more than 2,000 new rooms to its portfolio.
Online marketing director Mikel Otegui said: “We have a truly international offering, so need a marketing partner that can provide the highest quality affiliate network across multiple territories.
“Tradedoubler shares our international vision and brings unrivalled expertise in driving revenues through performance marketing for the travel sector. We are looking forward to expanding our international business with their support.”
Tradedoubler regional director Dan Cohen said: “NH Hoteles is growing fast and has a distinctive offering that customers’ enjoy.
“We’re confident that we can help NH Hoteles achieve their revenue and growth targets and help introduce the brand to a new customer base.”