Complex sentence: Its main competitors were more established no-frills carriers such as Ryanair and Easyjet, as well as other coeval low-cost startups such as Germanwings or transavia.com, consequently being constantly engaged in a price war with these carriers.
Split into simpler sentences: Its main competitors are more established no-frills carriers such as Ryanair and Easyjet, as well as other recent low-cost startups such as Germanwings and transavia.com. It is constantly engaged in a price war with these carriers.