Accor, Europe's largest hotel group, is planning to join forces with Gleneagles owner Ennismore to form what it says will be the world's largest operator of lifestyle hotels.
The combined business will act as a standalone entity comprised of 73 hotels under 12 brands, including the Hoxton and Mama Shelter, and more than 150 restaurants and bars.
To create the company Accor intends to spend more than $300m (£221m) to buy out its partners in sbe Entertainment Group, Mama Shelter and 25hours, taking full ownership of sbe's boutique hotel brands and much of its food and beverage arm.
This will see sbe's Mondrian, Delano, SLS and Hyde hotels form part of the new venture.
The combined company will be headquartered in London and operate under the name Ennismore.
The deal is expected to close in early 2021, subject to employee and regulatory approval.
If approved the newly formed company will have more than 110 further hotels in the pipeline, with around 70 under active discussion, and is expected to achieve earnings before interest, taxes, depreciation and amortisation of more than $100m (£74m) "in the mid term", according to Accor.
Sharan Pasricha, founder of Ennismore, and Gaurav Bhushan, chief executive of Accor's Lifestyle division, will be co-CEOs.
Accor will be majority shareholder, with Pasricha holding a substantial minority position.
Pasricha said: "This exciting autonomous entity with Accor – one with culture and brand purpose at its heart – allows us to come together to build on our combined portfolio of unique lifestyle brands, accelerate our growth and explore new markets."
Sébastien Bazin, chairman and chief executive of Accor, said lifestyle hotels had been "at the heart" of the group's development strategy over the past few years.
"Partnering with Ennismore's founder Sharan and his great teams will take our Lifestyle ambition to a new and exciting level. With this combination, we are leading the hospitality industry by creating the largest and fastest-growing ecosystem of world-class brands.
"This new powerful combination is set to become the engine of our exciting future growth."