Wheels Up, a private jet hire company backed by Serena Williams and Lance Armstrong, has announced plans to go public in a deal that will value the business at $2.1bn (£1.5bn). The company, which its founder describes as the “Uber of the sky”, said it had agreed a deal to float on the New York Stock Exchange via a merger with Aspirational Consumer Lifestyle Corp, a “blank cheque” special purpose acquisition company (Spac). The use of Spacs, shell companies which use proceeds from an initial public offerings to take a private firm public through the back door, has rocketed in recent months adding to mounting fears global stock markets may be in a bubble about to burst. Spacs are popular topics of conversation on Reddit message boards that have been thrust into focus over the hyping up of GameStop shares. Kenny Dichter, Wheels Up’s founder and chief executive, said he hoped the merger would turn the digital jet booking platform, which launched in 2013, into the “Uber of the sky”. “We are excited about crossing this milestone and our new partnership with Aspirational,” he added. “We believe this will allow us to actualise our founding goal of democratising private aviation, through our unique membership model, suite of products and benefits, and by bringing the shared economy to private aviation through our Wheels Up app. We are looking forward to joining forces with the Aspirational team as we continue to accelerate our global growth and expansion.” Wheels Up offers its customers a three-tier membership programme with reduced annual fees for new clients ranging from $2,995 to $29,500, excluding the cost of hiring a private jet. Delta Airlines, which has an equity stake in Wheels Up from the merger of Delta Private Jets with Wheels Up last year, will remain a shareholder when the deal is completed.