– CME Group Inc. rang the closing bell on open-outcry futures markets Monday after a few dozen Chicago traders donned their multicolored jackets to buy and sell soybean and Eurodollar futures the old-fashioned way one last time.

The world's largest futures exchange operator ended most of its open-outcry futures operations in Chicago and New York without an extended review from U.S. regulators, concluding a tradition that once epitomized global financial markets but succumbed to the efficiency and speed of machines.

The din of raucous shouting and frenzied hand gestures at CME's cavernous Chicago Board of Trade and Chicago Mercantile Exchange floors has faded over the years, and made up only 1 percent of total volume by this year. The exchanges' more active options pits will remain open for now, although they too are losing ground to electronic dealing.

Veteran traders returned to the grain floor in Chicago to witness the end of 167 years of open-outcry trading in the city where it was born. Many drifted into the octagonal trading pits before the closing bell after initially sharing stories on the sidelines.

"It felt like saying goodbye to an old friend, someone who'd been with you most of your adult life," said John Pietrzak, a corn broker for more than 35 years. He was the last person out of the corn futures pit.

The CME shut the pits despite resistance from a small group of floor brokers and traders in Chicago, who argued the closures would hurt end users in the Treasury and Eurodollar markets. Last month, they asked the U.S. Commodity Futures Trading Commission to open a 90-day review of the plan, but the CFTC said Monday it would not extend its review.

Longtime floor traders had wanted the CFTC to let the pits die as planned. They felt it was inevitable that the floor would eventually close because of the shift of business to computers.

"If it's gonna happen, it's gonna happen," said Tom Cashman, who has been on the grains floor in Chicago for more than 50 years.

Since the CME announced in February that it planned to close the futures pits in July, the trading floor has been through "the world's longest wake" with former traders and their families visiting to say goodbye, said Scott Shellady, who is in his 28th year of trading and wears a cow-patterned jacket on the CME's agricultural floor.

"Just close it," he said. "Take the Band-Aid off."