The US Supreme Court on Monday agreed to revisit an important part of the country’s patent system for the first time in nearly three decades, in a decision that legal experts said was likely to result in a move away from the more liberal approach to patenting that has held sway in recent years.

The case, over an attempt to patent a method for hedging the impact of changes in the weather on energy prices, had already come to be seen as an important test case in the controversial area of business method patenting. Applications for protection for new ways of doing business, often involving the use of technology, have exploded in recent years as the internet has brought novel business approaches and the US Patent and Trademark Office has become more lenient.