The group comprises five airlines: premium carriers Lufthansa, SWISS and Austrian Airlines; and budget airlines Brussels Airlines and Eurowings.
Black Diamond’s remit will focus on media relations, highlighting the airlines’ sustainability efforts, leadership in digital innovation, new route announcements and financial results, in addition to other newsworthy events and price campaigns.
The account will be overseen by acting head of travel PR Rae White, who will work alongside senior PR account manager Sophia Amos and senior PR executive Grace Verdon.
Lufthansa Group senior sales director Andreas Koester said the UK and Ireland are important markets for the group.
"We are excited to showcase these brands to the media through new and innovative opportunities with Black Diamond," Koester added.
"We are confident that this dynamic and creative agency will enable us to achieve our 2019 goals by leveraging existing and implementing new partnerships across the B2B and B2C spectrums."
Lufthansa is the world’s largest aviation group in terms of turnover and are the market leaders in Europe’s airline sector. Its network serves 343 destinations in 103 countries and totalling 15,415 routes across the North Atlantic, South America, Africa, Europe and the Far East.
The appointment comes hot on the heels of Visit Seattle, which appointed Black Diamond in January 2019.
Account lead White said the agency was thrilled to be chosen to work with Lufthansa. "Having the chance to work across such a prestigious brand portfolio presents a very exciting opportunity for us at Black Diamond," he said.
"We are looking forward to driving more awareness and recognition for Lufthansa, SWISS, Austrian Airlines, Brussels Airlines and Eurowings in what is an extremely important market for all."