Lufthansa Technik AG v Astronics Advanced Electronic Systems & Anor (Re Interest) [2025] EWHC 1034 (Pat)
This judgment concerns the question of whether as a matter of principle ancillary interest may be awarded upon sums found due in an account of profits for patent infringement.
The defendants had each been held liable for patent infringement: [2020] EWHC 1968 (Pat) & [2022] EWCA Civ 20. Leech J heard the ensuing account of profits [2025] EWHC 375 (Pat) and determined the relevant sums due for each defendant (see [1]-[4] of [2025] EWHC 1034 (Pat)). The question then arose as to Lufthansa’s entitlement to interest upon those sums.
Leech J held that the court has the power to award the payment of interest on sums found due following an account of profits for patent infringement, both pursuant to the court’s inherent equitable jurisdiction (see [6]-[12]) and (obiter) pursuant to s.35A Senior Courts Act 1981 (see [13]-[21]).
In addition to that question of principle, the Judge determined disputes relating to the amount of interest: namely discretion to award interest [22]-[25], delay [26]-[30], rate [31]-[35], tax upon interest [36]-[38], and the time from which interest should be calculated [39].
Further, against a background of multi-jurisdictional litigation between the parties in respect of products which in the ordinary course of trade pass through several jurisdictions, the issue arose as to how to address the risk of ‘double recovery’ of profits by the patentee. On the facts, the UK Patents Court was the first court to reach a decision on recoverable profits. The Judge elected not to render the account on a provisional basis with liberty to apply, preferring instead to leave the matter of double recovery for the overseas courts to address in their own decisions in due course (see [44]-[56] & [58]).
Hugo Cuddigan KC, Christopher Hall and Miruna Bercariu acted for Lufthansa. Iain Purvis KC and Piers Acland KC acted for Astronics, Safran and Panasonic.