"Let me get right to the point," wrote Ratterman. "Bats experienced a serious technical failure Friday morning and I want to apologise for not measuring up to the level of excellence that you have come to expect from us."

The break in trading was traced to a software bug in the open auction process that at one point sent Bats' share price careering downwards from $15 to less than a penny before trading was halted.

"After fixing the software module that failed, and rolling it back into production, we were faced with how the market would react to a re-opening of our stock after the failed first start," says Ratterman. "Had the delay been only a few minutes, the re-start process would have possibly been manageable. But after 2 ½ hours had transpired, we determined that this was a material event that had eroded investor confidence and made the timely resumption of fair and orderly trading unlikely. As a result, we pulled the IPO and unwound all auction executions."

The debacle has re-opened the debate over the ability of market mechanisms to cope with high frequency trading and angered Bats' shareholders and customers. In an e-mailed letter to customers, Bats' founder and former CEO Dave Cummings called for a suspension of all bonus plans at Bats and urged to the company to re-instigate the IPO for the second quarter.

"This was a freak one-time event," he wrote. "Bats management should develop a plan to go public in the second quarter, if possible. This might seem tough, but I believe it is the only way to move past the issue."

Ratterman carefully avoided the issue in his open letter, stating: "We take pride in our technology, and Friday's failure to perform as expected has no excuses...We owe it to all of you to do better and we will work even harder to earn your trust and confidence in the months and years ahead."

Despite the meltdown, Bats is continuing with its plans to switch Chi-X Europe - the venue for about one fifth of all share trading in the region - to its technology platform next month.