Litigation risk is a huge cost of doing business in America, and now things could be about to get much worse - not just for US companies, but for virtually any company anywhere that does business with a US-listed corporation.

Tomorrow the US Supreme Court will hear its most important securities case in a decade - a case that could subject businesses around the world to billions of dollars in new liability. For weeks, the US business community has beat a steady drum of alarm about the case, Stoneridge v Scientific-Atlanta , which tests whether third parties such as accountants, lawyers and even vendors can face private lawsuits for doing business with a US company that commits fraud.