Nasdaq OMX is in preliminary talks with US securities regulators over a potential settlement related to its botched handling of last year's Facebook stock market debut, according to people with knowledge of the discussions.

Nasdaq executives have been eager to put behind them an eight month investigation into technology errors that plagued the Nasdaq Stock Market on May 18, delaying the start of trading in Facebook shares that morning and ultimately costing brokers and investors an estimated $500m in losses.