The shareholding is currently held by a consortium of investors led by global investment firm Certares. A fee has not been disclosed.

Ama’s founders Rudi Schreiner, Kristin Karst and the Murphy family will retain "meaningful ownership" of the business following L Catterton’s investment.

All three "remain committed to supporting the company’s long-term growth" and supporting "innovation in the river cruising industry".

Meet Ama’s UK managing director Jamie Loizou

Co-founder and chief executive of AmaWaterways, Schreiner, said the deal would herald "an exciting new chapter" for the line.

Schreiner added L Catterton would bring "unique" consumer insights and exciting ideas to capitalise on growth opportunities in the river sector.

"We look forward to working with them to continuously expand and enhance our river cruise portfolio for our customers," said Schreiner.

Marc Magliacano, co-managing partner of L Catterton’s flagship fund, reiterated the goal of identifying and pursuing "new growth opportunities" and "thoughtful expansion initiatives" for AmaWaterways.

L Catterton partner Jennifer Reid said Ama’s offering continued to serve trade partners well, and hailed Schreiner and Karst – who co-founded the line with Jimmy Murphy – "true visionaries".

Colin Farmer, senior managing director and head of the Certares management committee, said the firm was proud of the role it had played in Ama’s growth, including enhancing its relationships with the trade.