REUTERS: A computer malfunction that forced the New York Stock Exchange to suspend trading for more than three hours on Wednesday probably stemmed from a software update that went awry, Bloomberg reported, citing two people briefed on a preliminary review.

The New York Stock Exchange, a unit of Intercontinental Exchange Inc, reopened at 3:10 p.m. EDT (1910 GMT) after being halted shortly after 11:30 a.m. EDT. NYSE said the outage was due to an internal technical issue and not the result of a cyberattack. Other exchanges were trading normally.

The NYSE must now verify the cause and report its conclusions to the U.S. Securities and Exchange Commission, which will use those findings to investigate whether any violation of rules occurred, Bloomberg reported. (http://bloom.bg/1LXzuAY)

A NYSE spokeswoman said the root cause of the trading halt was determined to be a “configuration issue.”

“Trading of NYSE-listed stocks continued on NYSE Arca and other U.S. trading venues throughout this process,” she said.

Reuters could not immediately reach the SEC for comment outside regular U.S. business hours.