Shares in Parmalat plummeted by around 20% yesterday after a US court awarded Citigroup a payout of more than $350m relating to the 2003 collapse of the Italian dairy giant.

Parmalat, which collapsed under the weight of €14bn debts in 2003 following the discovery of a €4bn black hole in its accounts, had been seeking damages of $2.2bn (£1.3bn) from Citi, which it accused of being complicit in the fraud.

However, the New Jersey court ruled in favour of counter-claims by Citi that it had been deceived by its client. It ordered Parmalat to pay $364m (£214m) in damages – the highest monetary award that could have been granted in the circumstances.

News of the judgment, delivered on 20 October, prompted shares in Parmalat to fall by 19.9% by close of trading yesterday, meaning the company’s value has dropped by almost half this year to around €2bn.

The dairy company, which emerged from bankruptcy in 2005, has outstanding cases also relating to its collapse involving Bank of America and accountancy firm Grant Thornton.