One of the last vestiges of the swashbuckling era of commodities floor trading is fading away.

CME Group, the world's largest futures market operator, said Wednesday it is closing most of its futures trading pits in Chicago and New York as electronic trading has become the overwhelmingly dominant way futures contracts are bought and sold. The move, which will take effect by July 2, brings to a close nearly 150 years of barking and jostling over the price of grain, oil and interest rate contracts.