NYSE error, alleged Goldman breach said unrelated

NEW YORK (Reuters) - The New York Stock Exchange said on Monday there was no connection between an alleged security breach at Goldman Sachs and an error that dropped the big investment bank from a trading report the exchange issued last week.

Nor are they related to a technical problem that hit Big Board floor brokers and extended the trading day by 15 minutes last Thursday, an NYSE spokesman said.

Former Goldman Sachs computer programer Sergey Aleynikov, who was released on bail on Monday, is accused of stealing secret trading codes from the New York-based bank.

The Big Board, run by NYSE Euronext, issued a report last week that inexplicably did not list Goldman among its most active program trading firms in the week ended June 26. Goldman often tops the weekly list, which measures computer-driven orders for large baskets of stocks.

"It appears Goldman Sachs reported data correctly, and that due to a system problem on our part, the firm's individual program trading was not included in our weekly report," NYSE spokesman Ray Pellecchia said.

The exchange will re-issue the report with the Goldman Sachs data later this week.

Pellecchia said the Aleynikov case was not related to NYSE's program trading report error. He had no comment on whether the exchange was in discussions with Goldman about the alleged security breach.

Pellecchia added neither the report's error nor the Aleynikov case were related to the connectivity problem that impacted orders and spurred the NYSE to extend trading by an extra 15 minutes on Friday.

The exchange -- the world's largest measured by the size of its listings -- resumed trading on Monday after working through the U.S. holiday weekend to resolve issues that had affected orders late last week.

The NYSE extended trading past its regular closing time of 4 p.m. to 4:15 p.m. on Thursday, which marked the year's lightest volume session, a day before the U.S. financial markets closed for the U.S. Independence Day holiday.

The extended session was announced within the last half hour of the market's regular closing time.

Floor brokers had trouble routing orders for more than an hour early on Thursday, according to the NYSE. During the regular session, the Big Board briefly halted trading in several stocks, including Regis Corp and Avon Products .

The problem followed two others at the NYSE -- one on June 12 and one on June 26. The errors come as the NYSE scrambles to retain market share and upgrade systems to keep pace with smaller, faster rivals such as BATS Exchange and Direct Edge.

Meanwhile, Pellecchia said the NYSE plans later this month to change the information on which it bases the program trading reports. It will provide more details on the change July 23.

Shares of NYSE Euronext closed down a penny at $26.06 on Monday.

(Reporting by Jonathan Spicer and Ellis Mnyandu, editing by Leslie Gevirtz)