The International Swaps and Derivatives Association lashed out on Wednesday over a series of South Korean court rulings that have extracted Korean companies from currency hedging contracts after the companies suffered heavy losses when the currency slid against the dollar.

South Korean companies filed about 160 lawsuits against 13 banks, including Standard Chartered, Citibank and HSBC, seeking to nullify currency derivatives contracts, known as Kiko (kick-in kick-out).