Hotel Engine Inc. has closed a $140 million Series C funding round, led by Permira at a $2.1 billion valuation.Hotel Engine operates a hotel booking platform for business travelers, offering financial incentives and flexibility to customers.The platform provides access to rooms at 750,000 hotels, allowing bookings for individuals, groups, and events.Hotel Engine plans to expand its platform with flight and car rental booking features, reflecting its focus on more than just hotel bookings.