Bats Global Markets Inc., the six-year-old equity exchange, canceled its initial public offering, stunning Wall Street after errors on its own computer systems derailed trading in the stock and forced a halt in Apple Inc.

"We believe withdrawing the IPO is the appropriate action to take for our company and our shareholders," Joe Ratterman, the chief executive officer, said in a statement. Asked if that meant Bats is no longer going public, Randy Williams, a company spokesman, replied by e-mail, "Yes, that's correct."

Pulling the IPO capped a day of missteps for the electronic exchange, beginning just as the shares were making their debut. Data received by Bloomberg around 11 a.m. in New York showed the stock, the first ever listed on its Lenexa, Kansas-based market, quoted at pennies after being priced yesterday at $16. Around the same time, a 100-share transaction in Apple was executed on Bats so far away from the market price that it triggered a halt.