Shares plummet 10.3% to £17.38 after a jury in the US ruled that the Basingstoke-based outfit had infringed two patents and broke an agreement formed with Inguran in 2012.
The issue surrounds Genus’ research into sexed semen technology, which helps provide farmers with milk producing female calves.
The court is yet to determine the terms on which Genus can use the patents, which expire in the mid-2020s.
If Genus had won the case analysts at Liberium had forecast it making £5 million of cost savings, around 10% of 2015’s earnings before interest and tax.
The broker also pondered if one-off financial damages could have been awarded to Genus.
Genus did prove Inguran, which trades as Sexing Technologies, had a monopoly in the US in the sexed bovine semen processing market but failed to prove it had suffered any injury as a result of that monopoly.
The three-week trial started on 1 August and Genus is waiting for the outcome of several other motions related to 2012’s semen sorting agreement.