Weil Gotshal & Manges and Quinn Emanuel Urquhart & Sullivan have secured a key win for the billionaire Barclays brothers and Irish businessman Derek Quinlain and a high-profile legal battle over iconic hotels the Berkeley, the Connaught and Claridge's.

The Court of Appeal judgment this morning (3 June) saw Lord Justices Arden, Moore-Bick and Rimer unanimously refuse to overturn aspects of the High Court's decision last year, when it dismissed the claims brought by property developer Patrick McKillen.

McKillen alleged that the Barclay brothers, companies controlled by them or directors, used unfair or prejudicial means to try to take control of Coroin – the hotels' holding company – bypassing McKillen's right to buy more shares.

Last August Mr Justice David Richards of the High Court ruled that McKillen's claims did not have any basis in fact or law. The decision followed the Court of Appeal's rulings against his favour in February and June last year.

McKillen, who is now liable to pay costs of around £18.7m, retains the right to appeal the decision to the Supreme Court.

Weil litigation partner Matthew Shankland, who led the litigation team acting for the Barclays brothers, said: "Mr McKillen has lost every major point in this appeal. His entire case has now been emphatically rejected in a series of judgments. The Barclay interests have been shown, beyond doubt, to have acted lawfully and fairly at all times in their dealings over Coroin."

Quinn Emanuel litigation partner Matthew Bunting, who was involved in acting for Coroin shareholder Quinlain, added: "This case has always been utterly misconceived, as should have been apparent to Mr McKillen and his advisors from the outset. We are pleased that both the High Court and Court of Appeal have agreed with us about this."

McKillen was represented by Herbert Smith Freehills. Other firms to have taken related roles on the case include DLA Piper, Ashurst, Hogan Lovells and Taylor Wessing.

DLA acted for Coroin while Hogan Lovells advised Ireland's National Asset Management Agency. Ashurst, meanwhile, acted for the directors representing the Barclays brothers on the board of Coroin, with Taylor Wessing advising the relevant trusts.